Hot TopicsWiley-VCH

ASCEurJOCChem Eur JAngewandte

Organocatalysis

ACh cover 24/2003The term organocatalysis describes the acceleration of chemical reactions through the addition of a substoichiometric quantity of an organic compound. The interest in this field has increased spectacularly in the last few years as result of both the novelty of the concept and, more importantly, the fact that the efficiency and selectivity of many organocatalytic reactions meet the standards of established organic reactions. Organocatalytic reactions are becoming powerful tools in the construction of complex molecular skeletons.[1,2]

[1] P. I. Dalko, L. Moisan,
Angew. Chem. 2001, 113, 3840; Angew. Chem. Int. Ed. 2001, 40, 3726
Angew. Chem. 2004, 116, 5248; Angew. Chem. Int. Ed. 2004, 43, 5138.

[2] Special issue of Adv. Synth. Catal. 2004, 346, Nr. 9-10.

Recent Articles

RSS feed

Nagaraju Mupparapu , Narsaiah Battini , Satyanarayana Battula , Shahnawaz Khan , Ram A. Vishwakarma , Qazi Naveed Ahmed 
Aminocatalytic Cross-Coupling Approach via Iminium Ions to Different C-C Bonds [Full Paper]

Aminocatalytic Cross-Coupling Approach via Iminium Ions to Different C-C Bonds

New iminium-ion reactivity mode: The reactivity of iminium ions containing an α C=O group, generated in situ by reaction of 2-oxoaldehydes with secondary amines, was developed and utilized to generate different cross-coupling products through formation of C-C and N-C bonds (see scheme). These processes proceed due to the unique ability of a three-component intermediate to undergo self-deamination and oxidation by air and, moreover, furnished the mildest possible approach to α-ketoamides.

Chem. Eur. J., December 18, 2014, DOI: 10.1002/chem.201405477

Solvent-Free One-Step Photochemical Hydroxylation of Benzene Derivatives by the Singlet Excited State of 2,3-Dichloro-5,6-dicyano-p-benzoquinone Acting as a Super Oxidant

Super photooxidant: Photoinduced hydroxylation of neat deaerated benzene derivatives to the corresponding phenols occurred under visible-light irradiation of 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ; see figure), which acts as a super photooxidant in the presence of water. The reactions are initiated by electron-transfer oxidation of benzene derivatives with the singlet and triplet excited states of DDQ to form the corresponding radical cations and DDQ..

Chem. Eur. J., December 18, 2014, DOI: 10.1002/chem.201404810

Organocatalytic Asymmetric Cascade Reactions of 7-Vinylindoles: Diastereo- and Enantioselective Synthesis of C7-Functionalized Indoles

Cascade reactions of 7-vinylindoles: The first catalytic asymmetric cascade reaction of 7-vinylindoles has been established by the rational design of such substrates. Cascade reactions with isatin-derived 3-indolylmethanols catalyzed by chiral phosphoric acid (CPA; see scheme) allow the diastereo- and enantioselective synthesis of C7-functionalized indoles as well as the construction of cyclopenta[b]indole and spirooxindole frameworks (all >95:5 d.r., 94–>99 % ee).

Chem. Eur. J., December 17, 2014, DOI: 10.1002/chem.201405245

Hong-Yu Wang, Kai Zhang, Chang-Wu Zheng, Zhuo Chai, Dong-Dong Cao, Jia-Xing Zhang, Gang Zhao
Asymmetric Dual-Reagent Catalysis: Mannich-type Reactions Catalyzed by Ion Pair [Communication]

Asymmetric Dual-Reagent Catalysis: Mannich-type Reactions Catalyzed by Ion Pair

Paired off: A new strategy, which combines a chiral phosphine with methyl acrylate to form a homogeneous ion pair, is introduced. This activation mode has been successfully applied to Mannich-type reactions, thus generating a variety of fluorinated amino acid derivatives in high yields and with high ee values.

Angew. Chem. Int. Ed., December 16, 2014, DOI: 10.1002/anie.201409342

Mineto Uchiyama, Kotaro Satoh, Masami Kamigaito
Cationic RAFT Polymerization Using ppm Concentrations of Organic Acid [Communication]

Cationic RAFT Polymerization Using ppm Concentrations of Organic Acid

Cationic RAFTing: A cationic reversible addition–fragmentation chain-transfer (RAFT) polymerization with thiocarbonylthio compounds proceeds in the presence of a small amount of CF3SO3H. Various monomers including vinyl ethers as well as alkoxy- and hydroxystyrene can be used. A transformation from cationic to radical RAFT polymerization enables the synthesis of block copolymers between cationically and radically polymerizable monomers.

Angew. Chem. Int. Ed., December 15, 2014, DOI: 10.1002/anie.201410858

Supramolecular Encapsulation of Neutral Diazoacetate Esters and Catalyzed 1,3-Dipolar Cycloaddition Reaction by a Self-Assembled Hexameric Capsule

Stuck in the middle: Diazoacetate esters are suitable neutral guests for the self-assembled resorcin[4]arene hexameric capsule. The hydrogen-bonded supramolecular host efficiently catalyzes 1,3-dipolar cycloadditions between such substrates and electron-poor alkenes, which leads to 4,5-dihydro-1H-pyrazole derivatives. The presence of competitive cationic guests for the capsule confirms that the reaction occurs within the cavity.

ChemCatChem, December 12, 2014, DOI: 10.1002/cctc.201402631

Joshua M. Wieting, Thomas J. Fisher, Andrew G. Schafer, Michael D. Visco, Judith C. Gallucci, Anita E. Mattson
Preparation and Catalytic Activity of BINOL-Derived Silanediols [Full Paper]

Preparation and Catalytic Activity of BINOL-Derived Silanediols

A family of BINOL-derived enantiopure silanediols has been prepared and studied. The effect of the substitution pattern of the BINOL backbone on catalyst performance is detailed. The acidities and chloride binding constants are also reported for this new and exciting class of hydrogen-bond donor (HBD) catalysts.

Eur. J. Org. Chem., December 11, 2014, DOI: 10.1002/ejoc.201403441

Artificial Flavin Systems for Chemoselective and Stereoselective Oxidations

This review covers the design and applications of artificial flavinium-based organocatalytic systems for chemoselective and stereoselective oxygenations with hydrogen peroxide and oxygen as stoichiometric oxidising agents.

Eur. J. Org. Chem., December 11, 2014, DOI: 10.1002/ejoc.201403275

Zhi-Qin Liang, Zhong-Hua Gao, Wen-Qiang Jia, Song Ye
Bifunctional N-Heterocyclic Carbene Catalyzed [3+4] Annulation of Enals and Aurones [Communication]

Bifunctional N-Heterocyclic Carbene Catalyzed [3+4] Annulation of Enals and Aurones

Stairway to seven: Bifunctional N-heterocyclic carbenes with a free hydroxy group are demonstrated as efficient catalysts for the [3+4] annulation of enals with aurones to give the corresponding benzofuran-fused ε-lactones in good yields with good diastereoselectivities and excellent enantioselectivities. Control experiments reveal that the [3+4] cycloadducts are kinetically favored and could be transformed to the thermodynamically favored [3+2] cycloadducts with a non-bifunctional NHC catalyst.

Chem. Eur. J., December 11, 2014, DOI: 10.1002/chem.201405828

Zamani E. D. Cele, Per I. Arvidsson, Hendrik G. Kruger, Thavendran Govender, Tricia Naicker
Applied Enantioselective Aminocatalysis: α-Heteroatom Functionalization Reactions on the Carbapenem (β-Lactam Antibiotic) Core [Full Paper]

Applied Enantioselective Aminocatalysis: α-Heteroatom Functionalization Reactions on the Carbapenem (β-Lactam Antibiotic) Core

A carbapenem intermediate serves as a useful nucleophile in organocatalyst-mediated α-heterofunctionalization reactions leading to the formation of diverse products.

Eur. J. Org. Chem., December 11, 2014, DOI: 10.1002/ejoc.201403238

Highly Enantioselective Intermolecular Cross Rauhut–Currier Reaction Catalyzed by a Multifunctional Lewis Base Catalyst

A cat. with handles: A multifunctional chiral Lewis base catalyst mediates the highly enantioselective intermolecular cross Rauhut–Currier reaction of different active olefins. The RC products were obtained in excellent yields and high chemo- and enantioselectivity. The reaction could be performed on a gram scale with a catalyst loading of 1 mol %.

Angew. Chem. Int. Ed., December 9, 2014, DOI: 10.1002/anie.201409744

Hendrik Büttner, Kornelia Lau, Anke Spannenberg, Thomas Werner
Bifunctional One-Component Catalysts for the Addition of Carbon Dioxide to Epoxides [Full Paper]

Bifunctional One-Component Catalysts for the Addition of Carbon Dioxide to Epoxides

Couple up: Recyclable bifunctional ammonium salts are identified as one-component catalysts for the 100 % atom-economic coupling reaction of CO2 and epoxides even at 45 °C. The alcohol moiety that donates a hydrogen bond accelerates the catalytic reaction remarkably. This metal and solvent-free process can be performed on a multigram scale and is applied to the synthesis of a naturally occurring cyclic carbonate.

ChemCatChem, December 9, 2014, DOI: 10.1002/cctc.201402816

Brønsted Acid-Catalyzed, Highly Enantioselective Addition of Enamides to In Situ-Generated ortho-Quinone Methides: A Domino Approach to Complex Acetamidotetrahydroxanthenes

With excellent enantio- and diastereoselectivity, acetamido-substituted tetrahydrobenzoxanthenes and related heterocycles are obtained in one synthetic operation. A specifically optimized chiral phosphoric acid converts ortho-hydroxy benzhydryl alcohols and enamides into highly functionalized target compounds carrying three contiguous chiral centers with typically good overall yields.

Chem. Eur. J., December 8, 2014, DOI: 10.1002/chem.201406044

Rongwei Jin, Frederic W. Patureau
Metal-free Dehydrogenative Isoquinolone Synthesis [Highlight]

Metal-free Dehydrogenative Isoquinolone Synthesis

Versatile C-H bonds: We discuss Manna and Antonchick’s metal-free isoquinolone synthesis through the dehydrogenative condensation of benzamides with alkynes and what it means for the fields of C-H functionalization and organic synthesis. DG=Directing group, E=electrophile.

ChemCatChem, December 8, 2014, DOI: 10.1002/cctc.201402704

Marek Dzięgielewski, Jakub Pięta, Elżbieta Kamińska, Łukasz Albrecht
Organocatalytic Synthesis of Optically Active Organophosphorus Compounds [Microreview]

Organocatalytic Synthesis of Optically Active Organophosphorus Compounds

Organophosphorus reagents play pivotal roles in modern organic synthesis and have found many applications for the preparation both of synthetically important compounds and of biologically relevant ones. They are now widely employed in asymmetric organocatalysis to afford optically active organophosphorus compounds. This review summarizes recent progress in this field of enantioselective synthesis.

Eur. J. Org. Chem., December 5, 2014, DOI: 10.1002/ejoc.201403184

Michael H. Anthofer, Michael E. Wilhelm, Mirza Cokoja, Markus Drees, Wolfgang A. Herrmann, Fritz E. Kühn
Hydroxy-Functionalized Imidazolium Bromides as Catalysts for the Cycloaddition of CO2 and Epoxides to Cyclic Carbonates [Communication]

Hydroxy-Functionalized Imidazolium Bromides as Catalysts for the Cycloaddition of CO2 and Epoxides to Cyclic Carbonates

Just a matter of H bonding: The efficient valorization of carbon dioxide to cyclic carbonates was performed under mild and metal-free conditions by activation of the epoxide through hydrogen bonding of a hydroxyl-functionalized bisimidazolium salt.

ChemCatChem, December 4, 2014, DOI: 10.1002/cctc.201402754

Takeshi Yamada, Tomoyasu Hirose, Satoshi Omura, Toshiaki Sunazuka
Organocatalytic α-Addition of Isocyanides to Aldehydes [Short Communication]

Organocatalytic α-Addition of Isocyanides to Aldehydes

3,5,6-Trifluoro-2-pyridone is an efficient catalyst for the α-addition of isocyanides to aldehydes in the presence of water in benzene. Various aldehydes and isocyanides performed well in this reaction to provide the α-hydroxyamides. Even highly constrained substrates were well tolerated. This is the first example of pyridone-catalyzed α-addition of isocyanides.

Eur. J. Org. Chem., December 2, 2014, DOI: 10.1002/ejoc.201403313

Asymmetric Synthesis of Fully Substituted Cyclopentane-Oxindoles through an Organocatalytic Triple Michael Domino Reaction

Triple Michael to pentagon! An organocatalytic three-component domino cyclization has been developed through a triple Michael sequence catalyzed by a secondary amine. Three bonds and six stereocenters, including a quaternary one, are formed by using equimolar reactants. A series of fully functionalized cyclopentane-oxindoles with potential bioactivity are obtained in good yields, very good diastereo-, and excellent enantioselectivities under mild conditions (see scheme).

Chem. Eur. J., December 2, 2014, DOI: 10.1002/chem.201406047

Highly Enantioselective Michael Addition of 2-Fluoro-1,3-diketones to Nitroalkenes

The asymmetric synthesis of fluorinated 1,3-diketones is achieved through quinine–sulfonamide mediated asymmetric Michael addition of racemic 2-fluoro-1,3-diketones to nitroalkenes. Subsequent stereoselective reduction of the carbonyl groups led to a functionalized fluoroisostere of the triol and generation of four stereogenic carbon centers, including one quaternary center, in two reaction steps.

Eur. J. Org. Chem., December 2, 2014, DOI: 10.1002/ejoc.201403361

Juho Bah, Veluru Ramesh Naidu, Johannes Teske, Johan Franzén
Carbocations as Lewis Acid Catalysts: Reactivity and Scope [Full Paper]

A Practical Aryl Unit for Azlactone Dynamic Kinetic Resolution: Orthogonally Protected Products and A Ligation-Inspired Coupling Process

Squared away: A strategy for enantioselective azlactone dynamic kinetic resolution to generate orthogonally protected amino acids has been developed. In the presence of a squaramide-based catalyst, benzyl alcohol reacts with tetrachloroisopropoxycarbonyl-substituted azlactones to generate phthalimide products with excellent enantiocontrol. Removal of the phthalimide can be achieved in the presence of the ester and vice versa.

Angew. Chem. Int. Ed., November 25, 2014, DOI: 10.1002/anie.201406857

Takasuke Mukaiyama, Kento Ogata, Tsuyoshi Ono, Yujiro Hayashi
Asymmetric Organocatalyzed Epoxidation of 2-Oxoindoline-3-ylidene Acetaldehydes [Full Paper]

Asymmetric Organocatalyzed Epoxidation of 2-Oxoindoline-3-ylidene Acetaldehydes

Giving metal catalysis the slip: The asymmetric epoxidation of 2-oxoindoline-3-ylidene acetaldehydes with hydrogen peroxide, catalyzed by diarylprolinol silyl ether, has been developed. Good to excellent diastereo- and enantioselectivities were realized even though the starting material 2-oxoindoline-3-ylidene acetaldehydes pre-existed as a mixture of E/Z-isomers.

ChemCatChem, November 24, 2014, DOI: 10.1002/cctc.201402811

A New Role for Sulfenate Anions: Organocatalysis

Introducing...Sulfenate! The sulfenate anion is introduced for the first time as a catalyst and was found to facilitate the conversion of benzyl halides to trans-stilbenes. CPME=Cyclopentyl methyl ether.

ChemCatChem, November 24, 2014, DOI: 10.1002/cctc.201402817

Phase-Transfer-Catalyzed Asymmetric SNAr Reaction of α-Amino Acid Derivatives with Arene Chromium Complexes

Increased substrate scope in phase-transfer-catalyzed asymmetric SNAr reactions was achieved by the use of arene chromium complexes as electrophiles. An efficient asymmetric synthesis of α,α-disubstituted α-amino acids containing various aromatic substituents is shown. PTC=phase-transfer catalyst.

Angew. Chem. Int. Ed., November 20, 2014, DOI: 10.1002/anie.201409065

Asymmetric Dearomatization of β-Naphthols through an Amination Reaction Catalyzed by a Chiral Phosphoric Acid

Useful skeletons: An electrophilic amination reaction catalyzed by chiral phosphoric acid is the basis for a highly efficient asymmetric dearomatization of naphthols. This protocol provides functionalized β-naphthalenone compounds with a chiral quaternary carbon center in excellent yields and enantioselectivity. These motifs are found in various biologically active natural products and therapeutic reagents.

Angew. Chem. Int. Ed., November 20, 2014, DOI: 10.1002/anie.201409756

Michal Majek, Axel Jacobi von Wangelin
Metal-Free Carbonylations by Photoredox Catalysis [Communication]

Metal-Free Carbonylations by Photoredox Catalysis

A metal-free and base-free carbonylation has been developed which affords primary, secondary, and tertiary alkyl benzoates under irradiation with visible light in the presence of eosin Y as a photocatalyst. The mechanism has been studied by spectroscopic, theoretical, and preparative methods, and appears to involve intermediate aryl and aroyl radical species as well as a light-driven one-electron redox cycle without any sacrificial redox partner.

Angew. Chem. Int. Ed., November 20, 2014, DOI: 10.1002/anie.201408516

Mohammed Kadraoui, Thibault Maunoury, Zoubir Derriche, Stéphane Guillarme, Christine Saluzzo
Isohexides as Versatile Scaffolds for Asymmetric Catalysis [Microreview]

Isohexides as Versatile Scaffolds for Asymmetric Catalysis

Two series of dianhydrohexitol derivatives, the first preserving the original bis-fused THF backbones and the second originating from single THF ring-opening reactions, are used as asymmetric ligands in organometallic catalysis or as asymmetric organocatalysts. Their synthesis and their application in different asymmetric reactions for the formation of C–H, C–C, C–N, and C–S bonds are discussed.

Eur. J. Org. Chem., November 17, 2014, DOI: 10.1002/ejoc.201402851

Joyram Guin, Qinggang Wang, Manuel van Gemmeren, Benjamin List
The Catalytic Asymmetric Abramov Reaction [Communication]

The Catalytic Asymmetric Abramov Reaction

A chiral disulfonimide catalyst is used to achieve the first catalytic enantioselective Abramov reaction. Several functionalized α-hydroxy phosphonates were synthesized in good yields and with excellent enantiomeric ratios of up to >99:1. The process was shown to be scalable and up to 1 g of starting material could be employed under mild reaction conditions.

Angew. Chem. Int. Ed., November 13, 2014, DOI: 10.1002/anie.201409411

N-Heterocyclic Carbene Catalyzed Enantioselective α-Fluorination of Aliphatic Aldehydes and α-Chloro Aldehydes: Synthesis of α-Fluoro Esters, Amides, and Thioesters

Two roles for NFSI: The N-heterocyclic carbene (NHC) catalyzed asymmetric fluorination of readily available simple aliphatic aldehydes, α-chloro aldehydes, and even alcohols proceeds via azolium enolates and yields a wide range of α-fluoro esters, amides, and thioesters with excellent enantioselectivity. N-Fluorobenzenesulfonimide (NFSI) acts as both a fluorinating reagent and an oxidant in this transformation.

Angew. Chem. Int. Ed., November 13, 2014, DOI: 10.1002/anie.201409961

Adrien Quintard, Diana Cheshmedzhieva, Maria del Mar Sanchez Duque, Anouk Gaudel-Siri, Jean-Valère Naubron, Yves Génisson, Jean-Christophe Plaquevent, Xavier Bugaut, Jean Rodriguez, Thierry Constantieux
Origin of the Enantioselectivity in Organocatalytic Michael Additions of β-Ketoamides to α,β-Unsaturated Carbonyls: A Combined Experimental, Spectroscopic and Theoretical Study [Full Paper]

Origin of the Enantioselectivity in Organocatalytic Michael Additions of β-Ketoamides to α,β-Unsaturated Carbonyls: A Combined Experimental, Spectroscopic and Theoretical Study

From theory to practise: The mechanism of asymmetric organocatalysed Michael addition of β-ketoamides to enones was studied theoretically, demonstrating for the first time the unique role of the hydrogen atom of the amide in controlling both the reactivity and the enantioselectivity (see scheme). Additional reactions afforded original spiro hemiaminals, taking advantage of the reactivity of the Michael adducts with acrolein. Post-functionalisation led to valuable enantioenriched glutarimides and pyridones.

Chem. Eur. J., November 7, 2014, DOI: 10.1002/chem.201404481

Synthesis and Evaluation of (S)-Proline-Containing α,β-Dipeptides as Organocatalysts in Solvent-Free Asymmetric Aldol Reactions Under Ball-Milling Conditions

A crushing victory: The organocatalytic activity of α,β-dipeptides 1 ac was evaluated in the asymmetric aldol reaction between ketones 2 and aldehydes 3. The best results in terms of yield and stereoselectivity were obtained under solvent-free conditions with ball-milling activation.

Asian J. Org. Chem., November 6, 2014, DOI: 10.1002/ajoc.201402170

Kerem Goren, Jeny Karabline-Kuks, Yael Shiloni, Einav Barak-Kulbak, Scott J. Miller, Moshe Portnoy
Multivalency as a Key Factor for High Activity of Selective Supported Organocatalysts for the Baylis–Hillman Reaction [Full Paper]

Multivalency as a Key Factor for High Activity of Selective Supported Organocatalysts for the Baylis–Hillman Reaction

Quantity into quality: A very strong manifestation of a positive multivalency effect on the catalytic activity is observed in dendritic polymer-supported catalysts, based on N-alkylimidazoles, in the Baylis–Hillman reaction (see scheme). Tethering the catalytically active units to a dendritic spacer enhances the activity per unit dramatically, sometimes by an order of magnitude.

Chem. Eur. J., November 5, 2014, DOI: 10.1002/chem.201404560

Chiral Ammonium Betaine-Catalyzed Highly Stereoselective Aza-Henry Reaction of α-Aryl Nitromethanes with Aromatic N-Boc Imines

What we need is tolerance: A highly stereoselective aza-Henry reaction of α-aryl nitromethanes with aromatic N-Boc imines was established by using C1-symmetric chiral ammonium betaine as a bifunctional organic base catalyst. The reaction tolerated various substituted aryl groups for both imines and nitromethanes, and a series of precursors for the synthesis of unsymmetrical anti-1,2-diaryl ethylenediamines was provided.

Chem. Asian J., October 22, 2014, DOI: 10.1002/asia.201402943

Enamine/Enolate-Mediated Organocatalytic Azide–Carbonyl [3+2] Cycloaddition Reactions for the Synthesis of Densely Functionalized 1,2,3-Triazoles

Organocatalytic click! Recent advances in the metal-free enamine/enolate-mediated azide–carbonyl [3+2] cycloaddition reaction are discussed. These approaches require neither a metal catalyst nor alkyne substrates. Owing to the ready availability of carbonyl compounds, these methods thus offer excellent alternatives for the synthesis of 1,4-/1,5-disubstituted and 1,4,5-trisubstituted 1,2,3-triazoles.

Angew. Chem. Int. Ed. 2014, 53, No. 52, 14310-14312

One-Pot Synthesis of Tri- and Tetrasubstituted Pyridines by Sequential Ring-Opening/Cyclization/Oxidation of N-Arylmethyl 3-Aziridinylpropiolate Esters

Small ring, big ring: A novel strategy for the one-pot synthesis of substituted pyridines from N-arylmethyl 3-aziridinylpropiolate esters is described. The method employs a three-step procedure including the formation of allenyl imines, phosphine-catalyzed cyclization, and subsequent oxidation of the dihydropyridines. Depending on the reaction conditions of the final oxidation step, tri- and tetrasubstituted pyridines can be selectively produced.

Angew. Chem. Int. Ed. 2014, 53, No. 52, 14550-14554

Guillem Valero, Josep M. Ribó, Albert Moyano
A Closer Look at Spontaneous Mirror Symmetry Breaking in Aldol Reactions [Full Paper]

A Closer Look at Spontaneous Mirror Symmetry Breaking in Aldol Reactions

Mirror, mirror on the wall! HPLC monitoring of the aldol reaction between 4-nitrobenzaldehyde and acetone (see figure) in the absence of a chiral catalyst reveals that spontaneous mirror symmetry breaking takes place initially in about 50 % of the reactions. A novel coupled reaction network that involves indirect autocatalysis and does not require heterochiral inhibition in the aldol product can explain this behavior.

Chem. Eur. J. 2014, 20, No. 52, 17395-17408

Lewis Base Catalyzed Aerobic Oxidative Intermolecular Azide–Zwitterion Cycloaddition

The works: The discovery of a novel aerobic oxidative intermolecular azide–zwitterion reaction catalyzed by an organocatalyst is presented. It is demonstrated that the merger of the Lewis base 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and electron-deficient olefins generates reactive zwitterion intermediates, which readily participate in cycloaddition reactions with an array of azides, thus providing facile entry to fully or highly substituted 1,2,3-triazole frameworks.

Angew. Chem. Int. Ed. 2014, 53, No. 51, 14186-14190

Yujiro Hayashi, Daichi Okamura, Tatsuya Yamazaki, Yasuto Ameda, Hiroaki Gotoh, Seiji Tsuzuki, Tadafumi Uchimaru, Dieter Seebach
A Theoretical and Experimental Study of the Effects of Silyl Substituents in Enantioselective Reactions Catalyzed by Diphenylprolinol Silyl Ether [Full Paper]

A Theoretical and Experimental Study of the Effects of Silyl Substituents in Enantioselective Reactions Catalyzed by Diphenylprolinol Silyl Ether

Typecast: Reactions catalyzed by diphenylprolinol silyl ether can be categorized into three types (see figure): two involve an iminium ion intermediate, such as for a Michael-type reaction (type A) and a cycloaddition reaction (type B), and one proceeds via an enamine intermediate (type C). In type A, good enantioselectivity is realized if a catalyst with a bulky silyl moiety is employed. In types B and C, good enantioselectivity is obtained even when the silyl group is less bulky.

Chem. Eur. J. 2014, 20, No. 51, 17077-17088

An Enolate-Mediated Organocatalytic Azide–Ketone [3+2]-Cycloaddition Reaction: Regioselective High-Yielding Synthesis of Fully Decorated 1,2,3-Triazoles

Fully functionalized 1,2,3-triazoles were synthesized by a metal-free clicking through an enolate-mediated organocatalytic azide–ketone [3+2]-cycloaddition (OrgAKC) reaction. Very simple and readily available aryl azides and enolizable arylacetones/deoxybenzoins were employed in this organocatalytic transformation (see scheme; DBU=1,8-diazabicyclo[5.4.0]undec-7-ene).

Chem. Eur. J. 2014, 20, No. 51, 16877-16881

Antoine Buchard, David R. Carbery, Matthew G. Davidson, Petya K. Ivanova, Ben J. Jeffery, Gabriele I. Kociok-Köhn, John P. Lowe
Preparation of Stereoregular Isotactic Poly(mandelic acid) through Organocatalytic Ring-Opening Polymerization of a Cyclic O-Carboxyanhydride [Communication]

Preparation of Stereoregular Isotactic Poly(mandelic acid) through Organocatalytic Ring-Opening Polymerization of a Cyclic O-Carboxyanhydride

Controlling tactic(s): The use of pyridine alone as the organocatalyst of the ring-opening polymerization (ROP) of a cyclic O-carboxyanhydride resulted in atactic poly(mandelic acid) (PMA), however, a well-defined pyridine/mandelic acid adduct enabled excellent control over the ROP, providing highly isotactic chiral PMA with an enhanced heat resistance. Tg=glass-transition temperature.

Angew. Chem. Int. Ed. 2014, 53, No. 50, 13858-13861

Junshan Tian, Jiankang Zhong, Yunsheng Li, Dawei Ma
Organocatalytic and Scalable Synthesis of the Anti-Influenza Drugs Zanamivir, Laninamivir, and CS-8958 [Communication]

Organocatalytic and Scalable Synthesis of the Anti-Influenza Drugs Zanamivir, Laninamivir, and CS-8958

A strategy to combat the flu: The anti-influenza drugs zanamivir and laninamivir (see structures) were synthesized in only 13 steps from inexpensive D-araboascorbic acid by the use of an organocatalytic Michael addition and a metal-catalyzed anti-selective Henry reaction as key transformations. This cost-effective, straightforward, and efficient approach enabled the synthesis of more than 3.5 g of zanamivir.

Angew. Chem. Int. Ed. 2014, 53, No. 50, 13885-13888

Yan Liu, Xiaobing Xi, Chengcheng Ye, Tengfei Gong, Zhiwei Yang, Yong Cui
Chiral Metal–Organic Frameworks Bearing Free Carboxylic Acids for Organocatalyst Encapsulation [Communication]

Chiral Metal–Organic Frameworks Bearing Free Carboxylic Acids for Organocatalyst Encapsulation

Two chiral carboxylic acid functionalized micro- and mesoporous metal–organic frameworks (MOFs) are constructed. The mesoporous MOF functions as a host for encapsulation of an enantiopure organic amine by acid–base interactions. The organocatalyst-loaded MOF is an efficient and recyclable heterogeneous catalyst for asymmetric direct aldol reactions, with significantly enhanced stereoselectivity relative to the homogeneous organocatalyst.

Angew. Chem. Int. Ed. 2014, 53, No. 50, 13821-13825

Yu-Chen Zhang, Jia-Jia Zhao, Fei Jiang, Si-Bing Sun, Feng Shi
Organocatalytic Asymmetric Arylative Dearomatization of 2,3-Disubstituted Indoles Enabled by Tandem Reactions [Communication]

Organocatalytic Asymmetric Arylative Dearomatization of 2,3-Disubstituted Indoles Enabled by Tandem Reactions

Less aromatic: The title reaction between indoles and quinone imine ketals was achieved by the two tandem approaches shown in the scheme. In both cases, enantiomerically pure indole derivatives bearing an all-carbon quaternary stereogenic center were generated in high yields and excellent stereoselectivities.

Angew. Chem. Int. Ed. 2014, 53, No. 50, 13912-13915

Asymmetric Disulfonimide-Catalyzed Synthesis of δ-Amino-β-Ketoester Derivatives by Vinylogous Mukaiyama–Mannich Reactions

Lewis acid catalysis: A chiral disulfonimide (DSI) serves as a highly efficient precatalyst for vinylogous Mukaiyama–Mannich reactions of a readily available silyloxydiene with protected imines, delivering δ-amino-β-ketoesters. The synthetic utility of the reaction is illustrated by the preparation of valuable enantiomerically enriched building blocks and the formal synthesis of (−)-lasubin.

Angew. Chem. Int. Ed. 2014, 53, No. 49, 13592-13595

Christian Brazel, Nathalie Dupré, Max Malacria, Bernold Hasenknopf, Emmanuel Lacôte, Serge Thorimbert
Intramolecular Anion Effect in Polyoxometalate-Based Organocatalysts: Reactivity Enhancement and Chirality Transfer by a Metal Oxide–Organic Cation Interaction [Communication]

Intramolecular Anion Effect in Polyoxometalate-Based Organocatalysts: Reactivity Enhancement and Chirality Transfer by a Metal Oxide–Organic Cation Interaction

A hybrid α1-Dawson polyanion bearing a lateral side chain with a 4-aminopyridine end group catalyzes the addition of indenyl allyl silanes to cinnamoyl fluorides. The chiral polyanionic framework influences the catalytic activity, the selectivity, and the stereoselectivity of the reaction (see figure).

Chem. Eur. J. 2014, 20, No. 49, 16074-16077

Zhichao Jin, Shaojin Chen, Yuhuang Wang, Pengcheng Zheng, Song Yang, Yonggui Robin Chi
β-Functionalization of Carboxylic Anhydrides with β-Alkyl Substituents through Carbene Organocatalysis [Communication]

β-Functionalization of Carboxylic Anhydrides with β-Alkyl Substituents through Carbene Organocatalysis

Nucleophilic carbon: NHC catalysis is used for the functionalization of carboxylic anhydrides. The β carbon acts as a nucleophilic carbon and undergoes asymmetric reactions with electrophiles. Anhydrides with challenging β-alkyl substituents work effectively.

Angew. Chem. Int. Ed. 2014, 53, No. 49, 13506-13509

Chiral Squaramide-Catalyzed Sulfa-Michael/Aldol Cascade for the Asymmetric Synthesis of Spirocyclic Tetrahydrothiophene Chromanone Derivatives

A bifunctional squaramide-catalyzed sulfa-Michael/aldol cascade reaction between benzylidenechroman-4-ones and 1,4-dithiane-2,5-diol has been developed. This reaction enables facile asymmetric access to chiral spirocyclic tetrahydrothiophene chromanone derivatives with three contiguous stereocenters in high to excellent yields (up to 99 %) and with high enantioselectivities (up to 92 % ee).

Eur. J. Org. Chem. 2014, No. 35, 7850-7858

Kenichi Murai, Junki Nakajima, Akira Nakamura, Norimichi Hyogo, Hiromichi Fujioka
Enantioselective, Desymmetrizing, Bromolactonization Reactions of Symmetric Olefinic Dicarboxylic Acids [Full Paper]

Enantioselective, Desymmetrizing, Bromolactonization Reactions of Symmetric Olefinic Dicarboxylic Acids

Mirror mirror on the wall: We have developed an enantioselective, desymmetrizing, bromolactonization reaction of symmetric olefinic dicarboxylic acids that is promoted by a C3-symmetric trisimidazoline organocatalyst.

Chem. Asian J. 2014, 9, No. 12, 3511-3517

Stereocontrolled Construction of the 3,4-Dihydrothiacarbazol-2(9H)-one Skeleton by Using Bifunctional Squaramide-Catalyzed Cascade Reactions

An efficient process for the enantioselective synthesis of optically active 3,4-dihydrothiacarbazol-2(9H)-one derivatives has been developed The cascade Michael addition/thiolysis reactions of 9-methylindoline-2-thiones and N-alkenoylphthalimides were promoted by a chiral bifunctional squaramide catalyst to give the desired products in acceptable yields with 54–98 % ee.

Eur. J. Org. Chem. 2014, No. 35, 7940-7947

Mesoporous Poly(melamine–formaldehyde): A Green and Recyclable Heterogeneous Organocatalyst for the Synthesis of Benzoxazoles and Benzothiazoles Using Dioxygen as Oxidant

Going round in heterocycles: Benzoxazole and benzothiazole derivatives are synthesized by using mesoporous poly(melamine–formaldehyde) as a green and recoverable catalyst. This heterogeneous organocatalytic method can provide a novel and efficient strategy for the synthesis of other N-heterocycles.

ChemCatChem 2014, 6, No. 12, 3434-3439

Rosaria Schettini, Brunello Nardone, Francesco De Riccardis, Giorgio Della Sala, Irene Izzo
Cyclopeptoids as Phase-Transfer Catalysts for the Enantioselective Synthesis of α-Amino Acids [Short Communication]

Cyclopeptoids as Phase-Transfer Catalysts for the Enantioselective Synthesis of α-Amino Acids

Cyclopeptoids are a novel class of efficient and tunable chiral macrocyclic phase-transfer catalyts. Screening of catalysts for the enantioselective alkylation of N-(diphenylmethylene)glycine tert-butyl ester shows the crucial role of N-arylmethyl residues.

Eur. J. Org. Chem. 2014, No. 35, 7793-7797

N-Heterocyclic Carbenes Supported on Vinylic Addition Polynorbornene: A Recyclable and Recoverable Organocatalyst

Three in one to ease organocatalysis: A robust, tunable, and recyclable organocatalytic system has been prepared by anchoring N-heterocyclic carbenes on an all-aliphatic vinylic addition polynorbornene (VA-PNB) scaffold. These three features make this heterogeneous NHC-based organocatalyst most convenient.

ChemCatChem 2014, 6, No. 12, 3547-3552

Promising Combination for Asymmetric Organocatalysis: Brønsted Acid-Assisted Chiral Phosphoric Acid Catalysis

Hand-in-hand: Recent developments in Brønsted acid-assisted chiral phosphoric acid catalysis are discussed, which exhibit the superiority of the self-assembly and the specificity of substrate recognition.

ChemCatChem 2014, 6, No. 12, 3309-3311

Qiying Zhang, Xiuling Cui, Lianmei Chen, Haitao Liu, Yangjie Wu
Syntheses of Chiral Ferrocenophanes and Their Application to Asymmetric Catalysis [Short Communication]

Syntheses of Chiral Ferrocenophanes and Their Application to Asymmetric Catalysis

The synthesis of ferrocenophane–amines is developed. Compound L1 can be used as a ligand in the the copper-catalyzed oxidative coupling of 3-hydroxy-2-naphthoate to give the product in good yield with up to 92 % ee, and it also efficiently catalyzes the asymmetric Michael addition reaction as an organocatalyst.

Eur. J. Org. Chem. 2014, No. 35, 7823-7829

Hydroxyl-Functionalized Imidazoles: Highly Active Additives for the Potassium Iodide-Catalyzed Synthesis of 1,3-Dioxolan-2-one Derivatives from Epoxides and Carbon Dioxide

A perfect combination: The combination of commercially available 4(5)-(hydroxymethyl)imidazole (HMI) and potassium iodide serves as a simple and efficient catalyst system for the coupling reaction of epoxides with carbon dioxide. Several epoxides are converted into cyclic carbonates in high yields (up to 99 %) under mild and solvent-free conditions within a short reaction time. This new catalyst system demonstrates higher activity than the previously reported potassium iodide/triethanolamine (TEA) system.

ChemCatChem 2014, 6, No. 12, 3493-3500

André Grossmann, Sean Bartlett, Matej Janecek, James T. Hodgkinson, David R. Spring
Diversity-Oriented Synthesis of Drug-Like Macrocyclic Scaffolds Using an Orthogonal Organo- and Metal Catalysis Strategy [Communication]

Diversity-Oriented Synthesis of Drug-Like Macrocyclic Scaffolds Using an Orthogonal Organo- and Metal Catalysis Strategy

Hand in hand: The outlined diversity-oriented synthesis of a library of macrocycles is based on the orthogonal combination of multiple diversity-generating organocatalytic steps with alkene metathesis. In total, 51 macrocyclic structures bearing 48 unique scaffolds, drug-like chemophysical properties, and natural-product-like shape diversity were synthesized in only 2 to 4 steps without the need for protecting groups.

Angew. Chem. Int. Ed. 2014, 53, No. 48, 13093-13097

Daniel T. Ziegler, Lorena Riesgo, Takuya Ikeda, Yuji Fujiwara, Gregory C. Fu
Biphenyl-Derived Phosphepines as Chiral Nucleophilic Catalysts: Enantioselective [4+1] Annulations To Form Functionalized Cyclopentenes [Communication]

Biphenyl-Derived Phosphepines as Chiral Nucleophilic Catalysts: Enantioselective [4+1] Annulations To Form Functionalized Cyclopentenes

All in the family: A new family of chiral nucleophilic catalysts, biphenyl-derived phosphepines, and their use in the title reaction is reported. A range of one-carbon coupling partners can be employed to generate cyclopentenes bearing a fully substituted stereocenter. Initial mechanistic studies are described.

Angew. Chem. Int. Ed. 2014, 53, No. 48, 13183-13187

Enantio- and Diastereoselective Access to Distant Stereocenters Embedded within Tetrahydroxanthenes: Utilizing ortho-Quinone Methides as Reactive Intermediates in Asymmetric Brønsted Acid Catalysis

Procedures for the Brønsted acid catalyzed asymmetric synthesis of 9-substituted tetrahydroxanthenones and 3,9-disubstituted tetrahydroxanthenone derivatives have been developed. The procedures are based on the in situ generation of ortho-quinone methides and their subsequent reaction with 1,3-dicarbonyl compounds. The reaction provides products with a high level of asymmetric induction.

Angew. Chem. Int. Ed. 2014, 53, No. 48, 13258-13263

María Sánchez-Roselló, Cristina Mulet, Marta Guerola, Carlos del Pozo, Santos Fustero
Microwave-Assisted Tandem Organocatalytic Peptide-Coupling Intramolecular aza-Michael Reaction: α,β-Unsaturated N-Acyl Pyrazoles as Michael Acceptors [Communication]

Microwave-Assisted Tandem Organocatalytic Peptide-Coupling Intramolecular aza-Michael Reaction: α,β-Unsaturated N-Acyl Pyrazoles as Michael Acceptors

The organocatalytic intramolecular aza-Michael reaction (IMAMR) with conjugated esters, elusive to date, was achieved by using N-acyl pyrazoles as ester surrogates (see scheme; DIC=diisopropyl carbodiimide, CPME=cyclopentyl methyl ether). Squaramides were the catalyst of choice, and the reaction was performed under microwave irradiation at 90 °C. Furthermore, the process could be also performed in a tandem peptide-coupling IMAMR starting from the corresponding conjugated carboxylic acid derivatives.

Chem. Eur. J. 2014, 20, No. 48, 15697-15701

Organocatalytic Asymmetric Mannich Cyclization of Hydroxylactams with Acetals: Total Syntheses of (−)-Epilupinine, (−)-Tashiromine, and (−)-Trachelanthamidine

Double bonanza: The title reaction in the presence of an imidazolidinone-based catalyst furnished N-bridgehead bicyclic alkaloids bearing [3.3.0], [3.4.0], [4.4.0], and [4.5.0] skeletons. By using this protocol, the total syntheses of (−)-epilupinine, (−)-tashiromine, and (−)-trachelanthamidine were achieved.

Angew. Chem. Int. Ed. 2014, 53, No. 48, 13196-13200

Jesús M. García, José M. Odriozola, Jesús Razkin, Irati Lapuerta, Amaiur Odriozola, Iñaki Urruzuno, Silvia Vera, Mikel Oiarbide, Claudio Palomo
Catalytic Enantioselective Quick Route to Aldol-Tethered 1,6- and 1,7-Enynes from ω-Unsaturated Aldehydes [Full Paper]

Catalytic Enantioselective Quick Route to Aldol-Tethered 1,6- and 1,7-Enynes from ω-Unsaturated Aldehydes

Ready to cyclize: Asymmetric synthesis of oxygenated 1,5- and 1,6-enynes is developed by means of an amine/Brønsted acid catalyzed direct cross-aldol reaction of unsaturated aldehydes. This reaction also works well with propargylic ketoesters yielding tertiary alcohols. Submission of the corresponding aldol adducts to standard O-silylation and subsequent Pauson–Khand conditions afforded the respective bicyclic products in good yields and stereoselectivities.

Chem. Eur. J. 2014, 20, No. 47, 15543-15554

Xiaoying Xu, Stephan M. Rummelt, Flavien L. Morel, Marco Ranocchiari, Jeroen A. van Bokhoven
Selective Catalytic Behavior of a Phosphine-Tagged Metal-Organic Framework Organocatalyst [Full Paper]

Selective Catalytic Behavior of a Phosphine-Tagged Metal-Organic Framework Organocatalyst

Selective catalysis by MOFs: Steric hindrance by a metal–organic framework (MOF) is shown to influence the outcome of a catalytic reaction by controlling the orientation of its intermediates, as demonstrated by using phosphine MOF LSK-3, which is evaluated with the aid of molecular modeling and NMR techniques and tested as a catalyst for coumarin synthesis, umpolung addition, Knoevenagel condensation, and [3+2] cycloaddition.

Chem. Eur. J. 2014, 20, No. 47, 15467-15472

Shoubhik Das, Felix D. Bobbink, Gabor Laurenczy, Paul J. Dyson
Metal-Free Catalyst for the Chemoselective Methylation of Amines Using Carbon Dioxide as a Carbon Source [Communication]

Metal-Free Catalyst for the Chemoselective Methylation of Amines Using Carbon Dioxide as a Carbon Source

The methylation of amines with CO2 as C1 source and Ph2SiH2 as reducing agent was achieved with an N-heterocyclic carbene (NHC) as the catalyst. The catalyst is tolerant toward a variety of functional groups (including esters and ethers, nitro, nitrile, and carbonyl groups, and unsaturated C-C bonds); the reaction uses commercially available reagents and can be performed on a gram scale.

Angew. Chem. Int. Ed. 2014, 53, No. 47, 12876-12879

Catalytic Asymmetric Construction of 3,3'-Spirooxindoles Fused with Seven-Membered Rings by Enantioselective Tandem Reactions

The catalytic asymmetric construction of a spirooxindole scaffold has been established by an organocatalytic three-component tandem reaction to provide structurally complex spirobenzodiazepine oxindoles with one quaternary stereogenic center (see scheme) in high yield with excellent enantioselectivity.

Chem. Eur. J. 2014, 20, No. 46, 15047-15052

María D. Díaz-de-Villegas, José A. Gálvez, Ramón Badorrey, Pilar López-Ram-de-Víu
Organocatalysis in Enantioselective α-Functionalization of 2-Cyanoacetates [Review]

High-Yielding Total Synthesis of Sexually Deceptive Chiloglottones and Antimicrobial Dialkylresorcinols through an Organocatalytic Reductive Coupling Reaction

Sexually deceptive chiloglottones, antimicrobial dialkylresorcinols, and their many analogues are synthesized in very good yields in a sequential two-pot manner by using an “organocatalytic reductive coupling reaction” as the key step.

Eur. J. Org. Chem. 2014, No. 33, 7317-7323

Applications of Carbohydrate-Based Organocatalysts in Enantioselective Synthesis

Carbohydrates, with their rigid backbones, large numbers of functional groups and high contents of chiral centres, are an appealing natural resource for the development of organocatalysts. They are becoming increasingly popular new tools for enantioselective synthesis, and this subject is reviewed for the period from 2009 to mid-2014.

Eur. J. Org. Chem. 2014, No. 33, 7291-7303

Organocatalyzed Asymmetric 1,4-Addition of Azlactones to α,β-Unsaturated Trichloromethyl Ketones: Synthesis of α,α-Disubstituted α-Amino Acid Derivatives

The first asymmetric 1,4-addition of azlactones to α,β-unsaturated trichloromethyl ketones by using cinchona alkaloid derived bifunctional thiourea catalysts is described. A series of α,α-disubstituted α-amino acid derivatives bearing a quaternary stereocenter at the α-position are obtained in high yields with excellent diastereo- and enantioselectivities (up to >20:1 dr and 99 % ee).

Eur. J. Org. Chem. 2014, No. 32, 7104-7108

Pedro C. Barrulas, Andrea Genoni, Maurizio Benaglia, Anthony J. Burke
Cinchona-Derived Picolinamides: Effective Organocatalysts for Stereoselective Imine Hydrosilylation [Short Communication]

Cinchona-Derived Picolinamides: Effective Organocatalysts for Stereoselective Imine Hydrosilylation

Cinchona derivatives for the successful enantioselective addition of trichlorosilane to ketimines are developed. Excellent yields with good to high enantioselectivities (up to 91 %) are obtained in the reduction of differently substituted substrates. Remarkably high turnover frequencies for imine hydrosilylation are observed at a catalyst loading of only 1 mol-%.

Eur. J. Org. Chem. 2014, No. 33, 7339-7342

Thomas Werner, Marcel Hoffmann, Sunetra Deshmukh
First Microwave-Assisted Catalytic Wittig Reaction [Short Communication]

First Microwave-Assisted Catalytic Wittig Reaction

The first catalytic Wittig reaction under microwave irradiation is reported. Readily available tributylphosphine oxide acts as the precatalyst. Under optimized conditions, a variety of aromatic, aliphatic, and heteroaromatic aldehydes could be converted efficiently. Moreover, one example of the first asymmetric version under these conditions is enclosed.

Eur. J. Org. Chem. 2014, No. 31, 6873-6876

Charles C. J. Loh, Pankaj Chauhan, Daniel Hack, Christian Lehmann, Dieter Enders
Rapid Asymmetric Synthesis of Highly Functionalized Indanols via a Michael/Henry Organocascade with Submol% Squaramide Catalyst Loadings [Update]

Ophélie Quinonero, Cyril Bressy, Xavier Bugaut
Organocatalytic Enantioselective Construction of Polyaromatic Architectures [Highlight]

Organocatalytic Enantioselective Construction of Polyaromatic Architectures

Aromatics in 3D: Organocatalysis is now reaching beyond the control of stereogenic centers and opens new possibilities for the construction of complex polyaromatic structures with either helical or axial chirality.

Angew. Chem. Int. Ed. 2014, 53, No. 41, 10861-10863

Applications of Chiral Phosphine-Based Organocatalysts in Catalytic Asymmetric Reactions

Out with the old: The design and synthesis of new chiral phosphines, as well as their application in catalytic asymmetric reactions, have recently drawn a lot of attention. This review summarizes the advances in the field of enantioselective phosphine organocatalysis within the last couple of years.

Chem. Asian J. 2014, 9, No. 10, 2720-2734

Sylvain Oudeyer, Jean-François Brière, Vincent Levacher
Progress in Catalytic Asymmetric Protonation [Microreview]

Progress in Catalytic Asymmetric Protonation

This review provides an overview of recent advances in catalytic enantioselective protonation of preformed enol derivatives and catalytically generated enolates or equivalents through various cascade reaction sequences giving access to a large range of enantioenriched compounds containing tertiary stereocentres.

Eur. J. Org. Chem. 2014, No. 28, 6103-6119

Rebecca L. Davis, Julian Stiller, Tricia Naicker, Hao Jiang, Karl Anker Jørgensen
Asymmetric Organocatalytic Epoxidations: Reactions, Scope, Mechanisms, and Applications [Minireview]

Asymmetric Organocatalytic Epoxidations: Reactions, Scope, Mechanisms, and Applications

Pick your type: In the past several decades, highly useful epoxidation protocols have been developed with a variety of activation modes using a wide range of asymmetric organocatalysts. This review documents the rapid and expansive development in this area, thus providing a clear overview of the various catalyst types available for asymmetric organocatalytic epoxidations, as well as their mechanisms and applications.

Angew. Chem. Int. Ed. 2014, 53, No. 29, 7406-7426

Gloria Rassu, Vincenzo Zambrano, Luigi Pinna, Claudio Curti, Lucia Battistini, Andrea Sartori, Giorgio Pelosi, Giovanni Casiraghi, Franca Zanardi
Direct and Enantioselective Vinylogous Michael Addition of α-Alkylidenepyrazolinones to Nitroolefins Catalyzed by Dual Cinchona Alkaloid Thioureas [Update]

Catalytic Asymmetric α-Hydroxyamination of Carbonyls with N-Hydroxycarbamates Becomes Greener

The power of two: A highly enantio- and regioselective aminocatalytic and Lewis acid catalyzed α-hydroxyamination of β-keto esters and 1,3-diketones with N-hydroxycarbamates is realized in “one-pot” under aerobic conditions. The powerful dual catalysis strategy opens opportunities for developing new efficient organic transformations. Cbz=Benzyloxycarbonyl, Boc=tert-butoxycarbonyl.

ChemCatChem 2014, 6, No. 07, 1863-1865

Tyler J. Auvil, Andrew G. Schafer, Anita E. Mattson
Design Strategies for Enhanced Hydrogen-Bond Donor Catalysts [Microreview]

Design Strategies for Enhanced Hydrogen-Bond Donor Catalysts

Since initial reports of organocatalysis through hydrogen bonding interactions, a number of strategies have emerged to allow access to enhanced hydrogen-bond donor (HBD) organocatalysts. These strategies range from augmentation of existing HBDs to the design and synthesis of new HBD catalysts. The effects of recent dual HBD designs on catalyst performance are described.

Eur. J. Org. Chem. 2014, No. 13, 2633-2646

Organocatalytic β-Functionalization of Saturated Carbonyl Compounds—the State of the Art

Get straight to the point! The elusive and direct organocatalytic β-functionalization of saturated carbonyl compounds has been tackled by oxidative enamine catalysis, oxidative NHC catalysis and merging of photoredox catalysis with organocatalysis. This new activation mode expanded the horizons of chemical synthesis and offers new insight for organic transformations and complex molecule synthesis.

ChemCatChem 2014, 6, No. 05, 1183-1185

Yao Li, Xin Li, Jin-Pei Cheng
Catalytic Asymmetric Synthesis of Chiral Benzofuranones [Review]

The Alternative Route to Enantiopure Multicomponent Reaction Products: Biocatalytic or Organocatalytic Enantioselective Production of Inputs for Multicomponent Reactions

This review describes an approach to enantiopure products based on the enantioselective generation, through biocatalysis or organocatalysis, of chiral substrates for a multicomponent reaction (MCR). If the chiral substrates are able to control the newly formed stereogenic centers, this strategy allows fast and diversity-oriented entry to complex chiral substrates.

Eur. J. Org. Chem. 2014, No. 10, 2005-2015

Andrea Gualandi, Luca Mengozzi, Claire M. Wilson, Pier Giorgio Cozzi
Synergy, Compatibility, and Innovation: Merging Lewis Acids with Stereoselective Enamine Catalysis [Focus Review]

Synergy, Compatibility, and Innovation: Merging Lewis Acids with Stereoselective Enamine Catalysis

The Perfect Storm! Water facilitates catalyst turnover in enamine organocatalysis, and it is generated during enamine formation. A synergy between Lewis acids and organocatalysts allows for the development of new, selective, and innovative processes, but water-compatible Lewis acids must be employed that are capable of surviving and maintaining activity in the presence of water.

Chem. Asian J. 2014, 9, No. 04, 984-995

Suqing Zheng, Casi M. Schienebeck, Wei Zhang, Hao-Yuan Wang, Weiping Tang
Cinchona Alkaloids as Organocatalysts in Enantioselective Halofunctionalization of Alkenes and Alkynes [Focus Review]

Cinchona Alkaloids as Organocatalysts in Enantioselective Halofunctionalization of Alkenes and Alkynes

You say goodbye, I say halo: Derivatives of cinchona alkaloids are an important class of organocatalysts. Their applications in asymmetric halofunctionalization of alkenes and alkynes are summarized in this Focus Review. A wide range of nucleophiles, halogenation reagents, and substituted alkenes, alkynes, or enynes can participate in these reactions to afford diverse chiral building blocks.

Asian J. Org. Chem. 2014, 3, No. 04, 366-376

Chiral 1,1'-Binaphthyl-2,2'-Disulfonic Acid (BINSA) and Its Derivatives for Asymmetric Catalysis

BINSA, done that: The Brønsted acidity of catalysts is considered to be associated with their catalytic activity. Therefore, chiral 1,1'-binaphthyl-2,2-disulfonic acid (BINSA) has recently received much attention as a strong chiral Brønsted acid catalyst. This Focus Review summarizes the latest achievements in chiral BINSA chemistry from the perspective of their synthesis and their catalytic use in asymmetric organocatalysis.

Asian J. Org. Chem. 2014, 3, No. 04, 352-365

Haiying Du, Jean Rodriguez, Xavier Bugaut, Thierry Constantieux
Organocatalytic Enantioselective Multicomponent Synthesis of Pyrrolopiperazines [Update]

Frédéric-Georges Fontaine, Marc-André Courtemanche, Marc-André Légaré
Transition-Metal-Free Catalytic Reduction of Carbon Dioxide [Concept]

Transition-Metal-Free Catalytic Reduction of Carbon Dioxide

Less is more: Metal-free systems, including frustrated Lewis pairs (FLPs), have been shown to bind CO2. By reducing the Lewis acidity and basicity of the ambiphilic system, it is possible to generate active catalysts for the deoxygenative hydroboration of carbon dioxide to methanol derivatives with conversion rates comparable to those of transition-metal-based catalysts (see scheme).

Chem. Eur. J. 2014, 20, No. 11, 2990-2996

N-Heterocyclic Carbene Catalyzed Activation of Esters: A New Option for Asymmetric Domino Reactions

Esters—what else! A new strategy in NHC organocatalysis allows the α-, β- and γ-activation of saturated and unsaturated esters. The resulting acyl azolium intermediates efficiently participate in domino reactions with suitable substrates to generate synthetically valuable carbo- and heterocycles with very good diastereo- and excellent enantioselectivities.

Angew. Chem. Int. Ed. 2014, 53, No. 06, 1485-1487

© Wiley-VCH 2013.