Hot TopicsWiley-VCH

EurJOCASCChem Eur JAngewandte

C–H Activation

The possibility of direct introduction of a new functionality (or a new C–C bond) via direct C–H bond transformation is a highly attractive strategy in covalent synthesis. The range of substrates is virtually unlimited, including hydrocarbons, complex organic compounds of small molecular weight, and synthetic and biological polymers. Below is a list of recent articles on this topic. For a review, see

  1. Xiao Chen, Keary M. Engle, Dong-Hui Wang, Jin-Quan Yu*
    Palladium(II)-Catalyzed C–H Activation/C–C Cross-Coupling Reactions: Versatility and Practicality
    Angew. Chem. 2009, 121, 5196–5217; Angew. Chem. Int. Ed. 2009, 48, 5094–5115

RSS feed

Recent Articles

Unprecedented Transformation of a Directing Group Generated In Situ and Its Application in the One-Pot Synthesis of 2-Alkenyl Benzonitriles

Directly functional! Cyanation and olefination was accomplished in one pot from benzoyl azides through an unprecedented directing group transformation. The method generates benzonitriles and can be used for the synthesis of 2-alkenylated benzonitrile derivatives (see scheme).

Chem. Eur. J., July 2, 2015, DOI: 10.1002/chem.201501449

Yudai Suzuki, Bo Sun, Ken Sakata, Tatsuhiko Yoshino, Shigeki Matsunaga, Motomu Kanai
Dehydrative Direct C-H Allylation with Allylic Alcohols under [Cp*CoIII] Catalysis [Communication]

Dehydrative Direct C-H Allylation with Allylic Alcohols under [Cp*CoIII] Catalysis

The unique reactivity of [Cp*CoIII] versus [Cp*RhIII] is showcased in the direct dehydrative C-H allylation with non-activated allyl alcohols. Cationic [Cp*CoIII] gave C2-allylated indoles, pyrrole, and phenyl-pyrazole in good yields, while the analogous [Cp*RhIII] catalysts were not effective. The high γ-selectivity and C2-selectivity result from directing-group-assisted C-H metalation, insertion of a C-C double bond, and subsequent β-hydroxide elimination. Cp*=C5Me5.

Angew. Chem. Int. Ed., July 1, 2015, DOI: 10.1002/anie.201503704

Acylation of (Hetero)Arenes through C-H Activation with Aroyl Surrogates

In splendid acylation: The major achievements in the acylation of arenes and heteroarenes by C-H activation with aroyl groups are summarized and discussed, based on the aroyl sources employed. In light of these achievements and their mechanistic studies, possible problems for carbonylative diaryl ketone synthesis by C-H activation are also discussed.

Chem. Eur. J., July 1, 2015, DOI: 10.1002/chem.201501548

Masashi Shigenobu, Kazuhiro Takenaka, Hiroaki Sasai
Palladium-Catalyzed Direct C-H Arylation of Isoxazoles at the 5-Position [Communication]

Palladium-Catalyzed Direct C-H Arylation of Isoxazoles at the 5-Position

Knock your 'sox' off: A palladium catalyst promotes the cross-coupling of isoxazoles with aryl iodides through the selective C-H bond activation at the 5-position of the heteroaromatic compound. The use of 1,2-bis(diphenylphosphino)benzene as the ligand and silver fluoride as the activator was found to be crucial for this direct arylation. FG=functional group.

Angew. Chem. Int. Ed., June 30, 2015, DOI: 10.1002/anie.201504552

Lutz F. Tietze, Bernd Waldecker, Dhandapani Ganapathy, Christoph Eichhorst, Thomas Lenzer, Kawon Oum, Sven O. Reichmann, Dietmar Stalke
Four- and Sixfold Tandem-Domino Reactions Leading to Dimeric Tetrasubstituted Alkenes Suitable as Molecular Switches [Communication]

Four- and Sixfold Tandem-Domino Reactions Leading to Dimeric Tetrasubstituted Alkenes Suitable as Molecular Switches

Highly efficient palladium-catalyzed fourfold tandem-domino reactions consisting of two carbopalladation and two C-H-activation steps were developed for the synthesis of two types of tetrasubstituted alkenes with intrinsic helical chirality. 20 different substrates were prepared with yields of up to 97 %. Photophysical investigations revealed light-induced switching properties of the products.

Angew. Chem. Int. Ed., June 26, 2015, DOI: 10.1002/anie.201503538

Wei Zheng, Bei-Bei Wang, Cheng-Hui Li, Jing-Xuan Zhang, Cheng-Zhang Wan, Jia-Hao Huang, Jian Liu, Zhen Shen, Xiao-Zeng You
Asymmetric Donor–π-Acceptor-Type Benzo-Fused Aza-BODIPYs: Facile Synthesis and Colorimetric Properties [Communication]

Asymmetric Donor–π-Acceptor-Type Benzo-Fused Aza-BODIPYs: Facile Synthesis and Colorimetric Properties

Dyes at the crossroads: By using tBuOK/DMF as base to ionize the phthalonitrile, we have developed a facile method to synthesize asymmetric donor–π-acceptor-type benzo-fused aza-BODIPY complexes. The newly prepared aza-BODIPYs exhibit novel colorimetric properties which could be attributed to the fracturing and restoration of the B-N bond.

Angew. Chem. Int. Ed., June 25, 2015, DOI: 10.1002/anie.201501984

Irina E. Iagafarova, Daria V. Vorobyeva, Alexander S. Peregudov, Sergey N. Osipov
CF3-Carbenoid C–H Functionalization of (Hetero)arenes under Chelation-Controlled RhIII Catalysis [Full Paper]

CF3-Carbenoid C–H Functionalization of (Hetero)arenes under Chelation-Controlled RhIII Catalysis

An efficient method for the CF3-carbenoid C–H functionalization of benzenes and indoles using readily available methyl 3,3,3-trifluoro-2-diazopropionate under chelation-controlled RhIII catalysis has been developed. The reaction proceeds with high regioselectivity and allows the simultaneous introduction of CF3 and COOMe groups into the 2-position of directing-group-containing benzenes and indoles.

Eur. J. Org. Chem., June 24, 2015, DOI: 10.1002/ejoc.201500545

RhIII-Catalyzed C(sp3)-H Bond Activation by an External Base Metalation/Deprotonation Mechanism: A Theoretical Study

Rounding the cycle: A theoretical investigation shows that the C(sp3)-H bond activation of methylquinoline with Cu(OAc)2 or free acetate occurs by an external base concerted metalation/deprotonation (CMD) mechanism (see scheme). The C-H activation is followed by cationic alkyne insertion.

Chem. Eur. J., June 23, 2015, DOI: 10.1002/chem.201501539

Gui-Juan Cheng, Ping Chen, Tian-Yu Sun, Xinhao Zhang, Jin-Quan Yu, Yun-Dong Wu
A Combined IM-MS/DFT Study on [Pd(MPAA)]-Catalyzed Enantioselective C-H Activation: Relay of Chirality through a Rigid Framework [Full Paper]

A Combined IM-MS/DFT Study on [Pd(MPAA)]-Catalyzed Enantioselective C-H Activation: Relay of Chirality through a Rigid Framework

Relay of chirality: A combined ion-mobility mass spectrometry (IM-MS) and DFT study has been carried out to investigate chiral Pd/monoprotected amino acid (MPAA)-enabled direct asymmetric C-H activation reactions. The enantioselectivity originates from the rigid square-planar Pd coordination in the C-H activation transition state: Bidentate MPAA and substrate coordination (see figure).

Chem. Eur. J., June 17, 2015, DOI: 10.1002/chem.201501123

Chemoselective Pd-Catalyzed Isocyanide Insertion Reaction of Enaminones by C–H Functionalization: Hydrolysis or Cyclization through 1,3-Palladium Migration

A chemoselective palladium-catalyzed isocyanide insertion reaction of enaminones was developed. Amide derivatives were synthesized by this C–H functionalization and subsequent hydrolysis reactions, and 4-aminoquinoline derivatives were prepared by this C–H functionalization, which includes a 1,3-palladium migration in the process.

Eur. J. Org. Chem., June 16, 2015, DOI: 10.1002/ejoc.201500458

Toan Dao-Huy, Birgit J. Waldner, Laurin Wimmer, Michael Schnürch, Marko D. Mihovilovic
Synthesis of endo- and exo-N-Protected 5-Arylated 2-Aminothiazoles through Direct Arylation: An Efficient Route to Cell Differentiation Accelerators [Full Paper]

Synthesis of endo- and exo-N-Protected 5-Arylated 2-Aminothiazoles through Direct Arylation: An Efficient Route to Cell Differentiation Accelerators

An improved protocol for the direct arylation of N-phenyl-N-benzyl(thiazol-2-yl)amines and regioisomeric 3-benzyl-N-phenylthiazol-2(3H)-imine is described. The two substrates for the arylation were obtained from a common starting material. In the latter case, the regioselectivity of arylation occurs exclusively in the 5-position.

Eur. J. Org. Chem., June 12, 2015, DOI: 10.1002/ejoc.201500283

Nickel-Catalyzed C-O/C-H Cross-Coupling Reactions for C-C Bond Formation

Halides not required: Nickel-catalyzed C-O/C-H cross-couplings for the construction of C-C bonds have recently been disclosed. By carefully optimizing the nickel catalyst, new C-C bond-forming reactions were developed, and even quaternary stereogenic centers are now accessible in high yields from readily available phenoxide derivatives and hydrocarbons.

Angew. Chem. Int. Ed., June 12, 2015, DOI: 10.1002/anie.201503204

A Theoretical Probe of Mechanistic Trichotomy in RhIII-Catalyzed Annulation with Alkyne MIDA Boronates: Roles of Salt, Solvent, and Coupling Partner

The reaction mechanisms, the role of salts, solvent effects, and substrate scope in the RhIII-catalyzed C–H activation and annulation of N-(pivaloyloxy)benzamide and alkyne MIDA boronates have been investigated by DFT calculations.

Eur. J. Org. Chem., June 12, 2015, DOI: 10.1002/ejoc.201500329

Metal-Free Dehydrogenative Diels–Alder Reactions of 2-Methyl-3-Alkylindoles with Dienophiles: Rapid Access to Tetrahydrocarbazoles, Carbazoles, and Heteroacenes

Setting a trap: Described is a strategy for in situ generation of indole-based ortho-quinodimethanes (oQDMs) from the title indoles through either a DDQ- or BQ-mediated dehydrogenative process. These oQDMs are trapped by electron-deficient olefins, thus providing facile access to tetrahydrocarbazoles, carbazoles, and hetereoacenes. BQ=benzoquinone, DDQ=2,3-dichloro-5,6-dicyano-1,4-benzoquinone.

Angew. Chem. Int. Ed., June 10, 2015, DOI: 10.1002/anie.201503549

Divergent Multicomponent Tandem Palladium-Catalyzed Aminocarbonylation-Cyclization Approaches to Functionalized Imidazothiazinones and Imidazothiazoles

Auto-tandem catalysis: A divergent multicomponent approach to imidazothiazinone and imidazothiazole derivatives starting from 2-(prop-2-ynylthio)imidazoles is developed. Imidazothiazinones are obtained from unsubstituted or monosubstituted substrates through an auto-tandem catalysis process that consists of two concatenated catalytic cycles, both catalyzed by PdI2.

ChemCatChem, June 10, 2015, DOI: 10.1002/cctc.201500213

Robin B. Bedford, Steven J. Durrant, Michelle Montgomery
Catalyst-Switchable Regiocontrol in the Direct Arylation of Remote C-H Groups in Pyrazolo[1,5-a]pyrimidines [Communication]

Catalyst-Switchable Regiocontrol in the Direct Arylation of Remote C-H Groups in Pyrazolo[1,5-a]pyrimidines

Remote control: Switching the regioselectivity of C-H arylation between remote sites on pyrazolo[1,5-a]pyrimidine can be achieved by tuning the structure of the catalyst. The control appears to be due to a change in mechanistic pathways between electrophilic palladation and base-assisted deprotonation.

Angew. Chem. Int. Ed., June 10, 2015, DOI: 10.1002/anie.201502150

Shuai Mao, Xue-Qing Zhu, Ya-Ru Gao, Dong-Dong Guo, Yong-Qiang Wang
Silver-Catalyzed Coupling of Two Csp3-H Groups and One-Pot Synthesis of Tetrasubstituted Furans, Thiophenes, and Pyrroles [Communication]

Silver-Catalyzed Coupling of Two Csp3-H Groups and One-Pot Synthesis of Tetrasubstituted Furans, Thiophenes, and Pyrroles

A three-ring circus: Silver-catalyzed coupling of two Csp3-H groups followed by cyclization have been developed. The approach provides a general and efficient access to tetrasubstituted furans, thiophenes, and pyrroles from easily accessible benzyl ketone derivatives in a one-pot reaction process.

Chem. Eur. J., June 10, 2015, DOI: 10.1002/chem.201501410

Palladium(II)-Catalyzed meta-C-H Olefination: Constructing Multisubstituted Arenes through Homo-Diolefination and Sequential Hetero-Diolefination

Jockeying for position: Reported herein is the palladium-catalyzed synthesis of mono- and divinylbenzenes by meta-C-H olefination of benzyl sulfones. Successful sequential olefinations in a position-selective manner provided a novel route for the synthesis of hetero-dialkenylated products, which are difficult to access using conventional methods. DG=directing group.

Angew. Chem. Int. Ed., June 9, 2015, DOI: 10.1002/anie.201503112

Hui-Jun Chen, Hong-Dong Hao, Yikang Wu
Conversion of Dihydroartemisinic Acid into Dihydro-epi-deoxyarteannuin B [Full Paper]

Conversion of Dihydroartemisinic Acid into Dihydro-epi-deoxyarteannuin B

The conversion of dihydroartemisinic acid into dihydro-epi-deoxyarteannuin B, a difficult transformation that defied exhaustive efforts in a previous study, can now be readily achieved in excellent yields with Pd(OAc)2/CuCl2/MnO2. This finding makes it easier to access a range of other arteannuins and several potent trioxane-type antimalarial agents.

Eur. J. Org. Chem., June 2, 2015, DOI: 10.1002/ejoc.201500291

Laurean Ilies, Saki Ichikawa, Sobi Asako, Tatsuaki Matsubara, Eiichi Nakamura
Iron-Catalyzed Directed Alkylation of Alkenes and Arenes with Alkylzinc Halides [Communication]

Cobalt(III)-Catalyzed Aryl and Alkenyl C-H Aminocarbonylation with Isocyanates and Acyl Azides

Clever cobalt: C-H aminocarbonylation of (hetero)arenes and alkenes was achieved by means of a user-friendly cobalt(III) catalyst. The reaction shows excellent chemo-, site-, and diastereoselectivity, as well as ample substrate scope.

Angew. Chem. Int. Ed., May 12, 2015, DOI: 10.1002/anie.201501926

Kosuke Takada, Tsurugi Hanataka, Takeshi Namikoshi, Shinji Watanabe, Miki Murata
Ruthenium-Catalyzed Dehydrogenative Aromatic C-H Silylation of Benzamides with Hydrosilanes [Communication]

Regioselective Syntheses of 1,2-Benzothiazines by Rhodium-Catalyzed Annulation Reactions

Domino effect: Rhodium-catalyzed annulation reactions provide 1,2-benzothiazines in excellent yields starting from S-aryl sulfoximines and diazo compounds. The catalysis shows a high functional-group tolerance and the process demonstrates excellent regioselectivity.

Angew. Chem. Int. Ed., April 14, 2015, DOI: 10.1002/anie.201501583

Ai-Hua Zhou, Fei Pan, Chunyin Zhu, Long-Wu Ye
Recent Progress towards Transition-Metal-Catalyzed Synthesis of Fluorenes [Minireview]

Recent Progress towards Transition-Metal-Catalyzed Synthesis of Fluorenes

Fluorene structures are commonly encountered in materials science, pharmaceutical chemistry, and organic synthesis. This Minireview summarizes how transition metal catalysis has become the prevalent strategy for the synthesis of fluorenes, as highlighted by examples from throughout the last decade.

Chem. Eur. J. 2015, 21, No. 29, 10278-10288

Yingjun Zhu, Michaela Bauer, Lutz Ackermann
Late-Stage Peptide Diversification by Bioorthogonal Catalytic C-H Arylation at 23 °C in H2O [Communication]

Late-Stage Peptide Diversification by Bioorthogonal Catalytic C-H Arylation at 23 °C in H2O

C-H arylation of oligopeptides was achieved in aqueous media under exceedingly mild reaction conditions. The chemo- and site-selective nature of the late-stage diversification protocol illustrates the potential of our strategy for peptide ligation and fluorescence labeling (see scheme).

Chem. Eur. J. 2015, 21, No. 28, 9980-9983

Sanjay Kumar Ghosh, Bing-Chiuan Kuo, Hsiang-Yu Chen, Jia-Ying Li, Shuang-De Liu, Hon Man Lee
Double C–H Functionalization to Construct Polycyclic Heteroarenes Catalyzed by an Ionic Salt of a Pd Complex with an N-Heterocyclic Carbene Ligand [Full Paper]

Double C–H Functionalization to Construct Polycyclic Heteroarenes Catalyzed by an Ionic Salt of a Pd Complex with an N-Heterocyclic Carbene Ligand

The complex cis-[Pd(L)(PPh3)(H2O)2](SO3CF3)2, in which L is an amido-functionalized N-heterocyclic carbene (NHC) ligand, has been prepared. This complex was effective in catalyzing the double C–H functionalization of various nitrogen- and sulfur-containing heteroarenes to form fused polycyclic heteroaromatic compounds with alkynes in the presence of Cu(OAc)2 and tetra-n-butylammonium bromide.

Eur. J. Org. Chem. 2015, No. 19, 4131-4142

Alexandre Vasseur, Jacques Muzart, Jean Le Bras
Ubiquitous Benzoquinones, Multitalented Compounds for Palladium-Catalyzed Oxidative Reactions [Microreview]

Ubiquitous Benzoquinones, Multitalented Compounds for Palladium-Catalyzed Oxidative Reactions

This review highlights the multifaceted properties of benzoquinone when it is involved in PdII-catalyzed oxidative reactions and presents mechanisms proposed in the literature.

Eur. J. Org. Chem. 2015, No. 19, 4053-4069

Keisuke Matsumura, Soichi Yoshizaki, Masato. M. Maitani, Yuji Wada, Yuhei Ogomi, Shuzi Hayase, Tatsuo Kaiho, Shinichiro Fuse, Hiroshi Tanaka, Takashi Takahashi
Rapid Synthesis of Thiophene-Based, Organic Dyes for Dye-Sensitized Solar Cells (DSSCs) by a One-Pot, Four-Component Coupling Approach [Full Paper]

Rapid Synthesis of Thiophene-Based, Organic Dyes for Dye-Sensitized Solar Cells (DSSCs) by a One-Pot, Four-Component Coupling Approach

All-in-one! A one-pot, four-component coupling approach was developed for the synthesis of thiophene-based, organic dyes (see scheme). Seven dyes were successfully synthesized in good yields under mild reaction conditions. Evaluation of photovoltaic properties revealed that the dyes containing either a n-hexyloxyphenyl amine donor or the developed, nonplanar donor without a 3,4-ethylenedioxythiophene (EDOT) moiety exerted good cell performance.

Chem. Eur. J. 2015, 21, No. 27, 9742-9747

Heteroatom-Guided, Palladium-Catalyzed, Site-Selective C-H Arylation of 4H-Chromenes: Diastereoselective Assembly of the Core Structure of Myristinin B through Dual C-H Functionalization

Straight to the point! A highly site- selective, heteroatom-guided, palladium-catalyzed direct arylation of 4H-chromenes is reported (see scheme). The C-H functionalization is driven not only by the substituents and structure of the substrate but also by the coupling partner being used. The diastereoselective assembly of the core structure of Myristinin B has been achieved by using a dual C-H functionalization strategy for regioselective direct arylation.

Chem. Eur. J. 2015, 21, No. 27, 9905-9911

David Dailler, Grégory Danoun, Benjamin Ourri, Olivier Baudoin
Divergent Synthesis of Aeruginosins Based on a C(sp3)-H Activation Strategy [Full Paper]

Divergent Synthesis of Aeruginosins Based on a C(sp3)-H Activation Strategy

Go natural! A general and scalable access to the aeruginosin family of marine natural products (see graphic), exhibiting potent inhibitory activity against serine proteases, is described. The strategic use of two different Pd-catalyzed C(sp3)-H activation reactions led to the synthesis of aeruginosins 98A–C and 298A.

Chem. Eur. J. 2015, 21, No. 26, 9370-9379

Yue He, Jincheng Mao, Guangwei Rong, Hong Yan, Guoqi Zhang
Iron-Catalyzed Esterification of Benzyl C-H Bonds to Form α-Keto Benzyl Esters [Update]

Fang Xie, Zhipeng Zhang, Xinzhang Yu, Guodong Tang, Xingwei Li
Diaryliodoniums by Rhodium(III)-Catalyzed C-H Activation: Mild Synthesis and Diversified Functionalizations [Communication]

Diaryliodoniums by Rhodium(III)-Catalyzed C-H Activation: Mild Synthesis and Diversified Functionalizations

Bonds aplenty: Diaryliodonium salts were synthesized for the first time from electron-poor arenes by the title reaction. The diaryliodoniums can be readily functionalized by nucleophiles with high chemoselectivity, thus leading to C-C, C-S, C-N, C-P, and C-Br bond formation. Cp*=C5Me5, DG=directing group, Ts=4-toluenesulfonyl.

Angew. Chem. Int. Ed. 2015, 54, No. 25, 7405-7409

Rhodium(III)-Catalyzed [4+1] Annulation of Aromatic and Vinylic Carboxylic Acids with Allenes: An Efficient Method Towards Vinyl-Substituted Phthalides and 2-Furanones

An efficient synthesis of highly substituted phthalides and 2-furanones from aryl and vinyl carboxylic acids with allenes by using a RhIII catalyst is demonstrated (see scheme). The reactions proceed through a carboxylate-assisted ortho-C-H activation and [4+1] annulation.

Chem. Eur. J. 2015, 21, No. 25, 9198-9203

Daniel G. Bachmann, Pascal J. Schmidt, Stefanie N. Geigle, Antoinette Chougnet, Wolf-Dietrich Woggon, Dennis G. Gillingham
Modular Ligands for Dirhodium Complexes Facilitate Catalyst Customization [Communication]

RhV-Nitrenoid as a Key Intermediate in RhIII-Catalyzed Heterocyclization by C-H Activation: A Computational Perspective on the Cycloaddition of Benzamide and Diazo Compounds

A calculated perspective: A mechanistic study of the 1,2,3,4,5-pentamethylcyclopentadienyl (Cp*)RhIII-catalyzed divergent cycloadditions of benzamide and diazo compounds was carried out by using DFT calculations (see scheme; Piv=pivalate; EWG=electron-withdrawing group).

Chem. Eur. J. 2015, 21, No. 25, 9209-9218

Ikuo Sasaki, Jumpei Taguchi, Shotaro Hiraki, Hajime Ito, Tatsuo Ishiyama
Catalyst-Controlled Regiodivergent C-H Borylation of Multifunctionalized Heteroarenes by Using Iridium Complexes [Full Paper]

Catalyst-Controlled Regiodivergent C-H Borylation of Multifunctionalized Heteroarenes by Using Iridium Complexes

Minor adjustments, major differences: The regiodivergent C-H borylation of 2,5-disubstituted heteroarenes with bis(pinacolato)diboron was achieved by using iridium catalysts formed in situ from [Ir(OMe)(cod)]2/dtbpy (cod=1,5-cyclooctadiene, dtbpy: 4,4'-di-tert-butyl-2,2'-bipyridine) or [Ir(OMe)(cod)]2/2 AsPh3 (see scheme).

Chem. Eur. J. 2015, 21, No. 25, 9236-9241

Tomoaki Yamaguchi, Eiji Yamaguchi, Norihiro Tada, Akichika Itoh
Direct ortho-Hydroxylation of 2-Phenylpyridines using Palladium(II) Chloride and Hydrogen Peroxide [Communication]

Xurong Qin, Xiaoyu Li, Quan Huang, Hu Liu, Di Wu, Qiang Guo, Jingbo Lan, Ruilin Wang, Jingsong You
Rhodium(III)-Catalyzed ortho C-H Heteroarylation of (Hetero)aromatic Carboxylic Acids: A Rapid and Concise Access to π-Conjugated Poly-heterocycles [Communication]

Rhodium(III)-Catalyzed ortho C-H Heteroarylation of (Hetero)aromatic Carboxylic Acids: A Rapid and Concise Access to π-Conjugated Poly-heterocycles

Under construction: The highly regioselective title reaction directly furnishes ortho-carboxy bi(hetero)aryls. The method has the potential to lead to the rapid construction of a library of appealing poly-heterocycles, given the complete regiocontrol, readily available substrates, and functional-group tolerance.

Angew. Chem. Int. Ed. 2015, 54, No. 24, 7167-7170

Karolina Graczyk, Tobias Haven, Lutz Ackermann
Iron-Catalyzed C(sp2)-H and C(sp3)-H Methylations of Amides and Anilides [Full Paper]

Iron-Catalyzed C(sp2)-H and C(sp3)-H Methylations of Amides and Anilides

Magic methyls: Expedient C-H methylations of (hetero)benzamides, alkenes, anilides, and even alkanes are realized with a broadly applicable and inexpensive iron catalyst by organometallic C(sp2)-H and C(sp3)-H activations (see scheme).

Chem. Eur. J. 2015, 21, No. 24, 8812-8815

Tsuyoshi Oshima, Iori Yamanaka, Anupriya Kumar, Junichiro Yamaguchi, Taeko Nishiwaki-Ohkawa, Kei Muto, Rika Kawamura, Tsuyoshi Hirota, Kazuhiro Yagita, Stephan Irle, Steve A. Kay, Takashi Yoshimura, Kenichiro Itami
C-H Activation Generates Period-Shortening Molecules That Target Cryptochrome in the Mammalian Circadian Clock [Communication]

C-H Activation Generates Period-Shortening Molecules That Target Cryptochrome in the Mammalian Circadian Clock

A change in rhythm: The first functional analysis of KL001 derivatives, which are mammalian circadian-clock modulators, was enabled by cutting-edge C-H activation. The sites of the KL001 derivatives that are critical for their rhythm-changing activity were elucidated, which led to the discovery of the first period-shortening molecules that target the cryptochrome.

Angew. Chem. Int. Ed. 2015, 54, No. 24, 7193-7197

Xuesong Liu, Linqian Yu, Mupeng Luo, Jidong Zhu, Wanguo Wei
Radical-Induced Metal-Free Alkynylation of Aldehydes by Direct C-H Activation [Communication]

Radical-Induced Metal-Free Alkynylation of Aldehydes by Direct C-H Activation

Direct C(sp2)-H activation of aldehyde C(O)-H bonds with hypervalent alkynyl iodides (G-EBX) provides ynones under metal-free conditions. 1-[(Triisopropylsilyl)ethynyl]-1,2-benziodoxol-3(1H)-one (TIPS-EBX) constitutes an efficient alkynylation reagent for the introduction of the triple bond.

Chem. Eur. J. 2015, 21, No. 24, 8745-8749

Divergent Reactivity in Palladium-Catalyzed Annulation with Diarylamines and α,β-Unsaturated Acids: Direct Access to Substituted 2-Quinolinones and Indoles

A basic diversion: A palladium-catalyzed C-H activation strategy is successfully employed for exclusive synthesis of 27 different 3-substituted indoles from α,β-unsaturated carboxylic acids and diarylamines under basic conditions in yields up to 89 %. Mechanistic studies revealed an ortho-palladation–π-coordination–β-migratory insertion–β-hydride elimination reaction sequence.

Chem. Eur. J. 2015, 21, No. 24, 8723-8726

Vincent Vreeken, Maxime A. Siegler, Bas de Bruin, Joost N. H. Reek, Martin Lutz, Jarl Ivar van der Vlugt
C-H Activation of Benzene by a Photoactivated NiII(azide): Formation of a Transient Nickel Nitrido Complex [Communication]

C-H Activation of Benzene by a Photoactivated NiII(azide): Formation of a Transient Nickel Nitrido Complex

Triple N: Photolysis of nickel-azido complex [Ni(N3)(PNP)] (2) in benzene results in a transient NiIV nitrido species that bears significant nitridyl character, as supported by DFT calculations. Subsequent insertion of the nitrogen into a Ni-P bond, followed by Csp2-H activation of solvent yields diamagnetic [Ni(Ph)(PNPNH)] (3) featuring a parent iminophosphorane ligand. Reaction with HCl provides well-defined [Ni(Cl)(PNPNH)] (4).

Angew. Chem. Int. Ed. 2015, 54, No. 24, 7055-7059

Sara Ruiz, Pedro Villuendas, Manuel A. Ortuño, Agustí Lledós, Esteban P. Urriolabeitia
Ruthenium-Catalyzed Oxidative Coupling of Primary Amines with Internal Alkynes through C-H Bond Activation: Scope and Mechanistic Studies [Full Paper]

Ruthenium-Catalyzed Oxidative Coupling of Primary Amines with Internal Alkynes through C-H Bond Activation: Scope and Mechanistic Studies

Efficiency of ruthenium: The oxidative coupling of primary amines with internal alkynes catalyzed by Ru complexes is presented as a general atom-economical methodology with a broad scope of applications in the synthesis of N-heterocycles (see figure). DFT calculations support a reaction mechanism that consists of acetate-assisted C-H bond activation, migratory-insertion, and C-N bond-formation steps.

Chem. Eur. J. 2015, 21, No. 23, 8626-8636

Asymmetric Nickel-Catalysed Cross-Hydrovinylation of Two Terminal Alkenes

Pushing the boundaries: The asymmetric 1,2-hydrovinylation of styrene derivatives with terminal alkenes is realised by using a nickel catalyst and specially designed chiral NHC ligands to achieve a new level of complexity for the tail-to-tail cross-coupling of alkenes by C-H activation.

ChemCatChem 2015, 7, No. 11, 1639-1641

Palladium-Catalyzed [3+3] Annulation between Diarylamines and α,β-Unsaturated Acids through C-H Activation: Direct Access to 4-Substituted 2-Quinolinones

4-Substituted 2-quinolinone species were synthesized in high yields by a palladium-catalyzed dehydrogenative coupling involving diarylamines. This intermolecular annulation approach incorporates readily available α,β-unsaturated carboxylic acids as the coupling partner by suppressing decarboxylation.

Chem. Eur. J. 2015, 21, No. 23, 8360-8364

Isomerization of Olefins Triggered by Rhodium-Catalyzed C-H Bond Activation: Control of Endocyclic β-Hydrogen Elimination

Control of endocyclic β-H elimination of a pivotal five-membered metallacycle enables the rhodium-catalyzed isomerization of 4-pentenals into 3-pentenals without decarbonylation and leads to trans olefins with exquisite selectivity. Other sensitive olefins, even if prone to isomerization, remain intact. Endocyclic β-H elimination can also be prevented, in which case an enantiodivergent reaction on the racemic substrate was observed.

Angew. Chem. Int. Ed. 2015, 54, No. 23, 6870-6873

Kenta Saito, Prasanna Kumara Chikkade, Motomu Kanai, Yoichiro Kuninobu
Palladium-Catalyzed Construction of Heteroatom-Containing π-Conjugated Systems by Intramolecular Oxidative C-H/C-H Coupling Reaction [Communication]

Palladium-Catalyzed Construction of Heteroatom-Containing π-Conjugated Systems by Intramolecular Oxidative C-H/C-H Coupling Reaction

Up the ladder: Synthesis of heteroatom-containing ladder-type π-conjugated molecules was successfully achieved via palladium-catalyzed intramolecular oxidative C-H/C-H cross-coupling reaction (see scheme). This reaction provides a variety of π-conjugated molecules bearing heteroatoms, such as nitrogen, oxygen, phosphorus, and sulfur atoms, and a carbonyl group.

Chem. Eur. J. 2015, 21, No. 23, 8365-8368

Synthesis of Iron Hydrides by Selective C–F/C–H Bond Activation in Fluoroarylimines and Their Applications in Catalytic Reduction Reactions

The selective activation of C–H/C–F bonds was realized in the reactions of Fe(PMe3)4 with fluorophenylimines by controlling the substituents of the fluorophenylimines. Iron hydrides were obtained through C–F bond activation with the assistance of silanes. These iron hydrides show excellent catalytic activity in the hydrosilylations of aldehydes, ketones, and α,β-unsaturated aldehydes.

Eur. J. Inorg. Chem. 2015, No. 16, 2732-2743

Tung T. Dang, Mickaële Bonneau, J. A. Gareth Williams, Hubert Le Bozec, Henri Doucet, Véronique Guerchais
Pd-Catalyzed Functionalization of the Thenoyltrifluoroacetone Coligands by Aromatic Dyes in Bis(cyclometallated) IrIII Complexes: From Phosphorescence to Fluorescence? [Full Paper]

Pd-Catalyzed Functionalization of the Thenoyltrifluoroacetone Coligands by Aromatic Dyes in Bis(cyclometallated) IrIII Complexes: From Phosphorescence to Fluorescence?

Bis(cyclometallated) IrIII complexes featuring acetylacetonate-type ligands directly conjugated to dyes are prepared by an original synthesis. The introduction of an aromatic pendant promotes fluorescence from the singlet state of the functionalized OO unit.

Eur. J. Inorg. Chem. 2015, No. 18, 2956-2964

Palladium-Catalyzed C2-Acylation of Indoles with α-Diketones Assisted by the Removable N-(2-Pyrimidyl) Group

A variety of 2-acylindoles were readily prepared from N-pyrimidyl-substituted indoles in moderate to good yields by an effective palladium-catalyzed C2-acylation method. The remarkable features of this methodology include good product yields and wide tolerance of various functional groups.

Eur. J. Org. Chem. 2015, No. 17, 3743-3750

Rayavarapu Padmavathi, Rathinam Sankar, Bojan Gopalakrishnan, Ramarao Parella, Srinivasarao Arulananda Babu
Pd(OAc)2/AgOAc Catalytic System Based Bidentate Ligand Directed Regiocontrolled C–H Arylation and Alkylation of the C-3 Position of Thiophene- and Furan-2-carboxamides [Full Paper]

Pd(OAc)2/AgOAc Catalytic System Based Bidentate Ligand Directed Regiocontrolled C–H Arylation and Alkylation of the C-3 Position of Thiophene- and Furan-2-carboxamides

A contemporary method is reported for the Pd(OAc)2/AgOAc catalytic system based bidentate ligand directed, regioselective C–H activation and C–C bond formation of the C-3 position of thiophene- and furan-2-carboxamides. This protocol was used for the direct C-3 arylation and alkylation reactions of both thiophene- and furan-2-carboxamides.

Eur. J. Org. Chem. 2015, No. 17, 3727-3742

Palladium(0)/PAr3-Catalyzed Intermolecular Amination of C(sp3)-H Bonds: Synthesis of β-Amino Acids

Zero in: The title reaction begins with oxidative addition of R2N-OBz to a Pd0/PAr3 catalyst and subsequent cleavage of a C(sp3)-H bond by the generated Pd-NR2 intermediate. The catalytic cycle proceeds without the need for external oxidants. The electron-deficient triarylphosphine ligand is crucial for this C(sp3)-H amination reaction to occur. Bz=benzoyl.

Angew. Chem. Int. Ed. 2015, 54, No. 22, 6545-6549

Natsuyo Kamimoto, Dieter Schollmeyer, Koichi Mitsudo, Seiji Suga, Siegfried R. Waldvogel
Palladium-Catalyzed Domino C-H/N-H Functionalization: An Efficient Approach to Nitrogen-Bridged Heteroacenes [Full Paper]

Palladium-Catalyzed Domino C-H/N-H Functionalization: An Efficient Approach to Nitrogen-Bridged Heteroacenes

Extended heteroacenes: A twofold arylation protocol for the efficient synthesis of 9H-benzo[4,5]thieno[3,2-b]thieno[3,4-d]pyrroles and 10H-benzo[4,5]thieno[3,2-b]indoles was developed (see scheme). The selectivity of this novel sequence allows the construction of highly π-extended heteroacenes.

Chem. Eur. J. 2015, 21, No. 22, 8257-8261

Stephen P. Cooper, Kevin I. Booker-Milburn
A Palladium(II)-Catalyzed C-H Activation Cascade Sequence for Polyheterocycle Formation [Communication]

A Palladium(II)-Catalyzed C-H Activation Cascade Sequence for Polyheterocycle Formation

Don't overdo it: A palladium(II)-catalyzed C-H activation cascade sequence for the synthesis of polyheterocycles is reported. Aromatization of the initially formed dihydro species occurred with a quinone oxidant. In some cases the use of one equivalent of the oxidant enabled isolation of the dihydro species as a single isomer (see scheme; X=NMe, O, S).

Angew. Chem. Int. Ed. 2015, 54, No. 22, 6496-6500

Intermolecular C-H Bond Activation by a Cationic Iridium(III) Dichloride Phenanthroline Complex

Iridium(III) unleashed: A cationic phenanthroline complex of IrIII can cleave C-H bonds of unactivated secondary carbons as well as benzylic carbons but not bonds to sp2 or primary carbons in the gas phase. The unique reactivity pattern likely stems from the suboptimum bite angle provided by the phenanthroline ligand. Computational modeling suggests that the C-H activation process is concerted, without a stable oxidative addition intermediate.

Angew. Chem. Int. Ed. 2015, 54, No. 22, 6475-6478

Shinsuke Okada, Takeshi Namikoshi, Shinji Watanabe, Miki Murata
Ruthenium-Catalyzed Ortho-Selective Aromatic C-H Borylation of 2-Arylpyridines with Pinacolborane [Communication]

Ruthenium-Catalyzed Ortho-Selective Aromatic C-H Borylation of 2-Arylpyridines with Pinacolborane

A ruthenium for C-H borylation: The ruthenium-catalyzed dehydrogenative borylation of 2-arylpyridines with pinacolborane took place at ortho-positions of the benzene ring.

ChemCatChem 2015, 7, No. 10, 1531-1534

Stefano Protti, Maurizio Fagnoni, Davide Ravelli
Photocatalytic C-H Activation by Hydrogen-Atom Transfer in Synthesis [Minireview]

Photocatalytic C-H Activation by Hydrogen-Atom Transfer in Synthesis

HATs off to photocatalysis! This review covers the recent advancements in the field of photocatalytic hydrogen-atom transfer (HAT) processes for C-H bond functionalization. Applications in organic synthesis, including the formation of C-C, as well as C-halogen, C-O (C=O) and C-N bonds, are presented.

ChemCatChem 2015, 7, No. 10, 1516-1523

Marc Moselage, Nicolas Sauermann, Sven C. Richter, Lutz Ackermann
C-H Alkenylations with Alkenyl Acetates, Phosphates, Carbonates, and Carbamates by Cobalt Catalysis at 23 °C [Communication]

C-H Alkenylations with Alkenyl Acetates, Phosphates, Carbonates, and Carbamates by Cobalt Catalysis at 23 °C

Inexpensive cobalt catalysis enabled the C-H alkenylation of unactivated (hetero)arenes with enol derivatives at ambient temperature. The versatile cobalt catalyst was employed for challenging C-H/C-O cleavage reactions with alkenyl acetates, carbamates, carbonates, and phosphates in a stereoconvergent fashion.

Angew. Chem. Int. Ed. 2015, 54, No. 21, 6352-6355

Gabriel Theurkauff, Arnaud Bondon, Vincent Dorcet, Jean-François Carpentier, Evgueni Kirillov
Heterobi- and -trimetallic Ion Pairs of Zirconocene-Based Isoselective Olefin Polymerization Catalysts with AlMe3 [Communication]

Heterobi- and -trimetallic Ion Pairs of Zirconocene-Based Isoselective Olefin Polymerization Catalysts with AlMe3

Zirconocene-based AlMe3 adducts bind an additional AlMe3 molecule reversibly, affording heterotrimetallic intermediates. One of the AlMe3 adducts undergoes slow decomposition via C-H activation in a bridging methyl unit to yield a new species with a trimetallic {Zr(μ-CH2)(μ-Me)AlMe(μ-Me)AlMe2} core.

Angew. Chem. Int. Ed. 2015, 54, No. 21, 6343-6346

Werner Uhl, Anne Hentschel, Dirk Kovert, Jutta Kösters, Marcus Layh
Heterocyclic Digallanates, Encapsulation of Lithium Cations in Organometallic Cages and C–H Bond Activation [Full Paper]

Heterocyclic Digallanates, Encapsulation of Lithium Cations in Organometallic Cages and C–H Bond Activation

C–H bond activation and ortho-metallation was achieved by heating novel macrocyclic phenylene centered dilithium di(galliumalkenyl) compounds in solution. The products contained five-membered GaC4 heterocycles. Various Li–π interactions resulted in fascinating molecular structures for the digallanate intermediates and the finally isolated metallacycles.

Eur. J. Inorg. Chem. 2015, No. 14, 2486-2496

Reactivity Diversification – Synthesis and Exchange Reactions of Cobalt and Iron 2-Alkenylpyridine/-pyrazine Complexes Obtained by Vinylic C(sp2)–H Activation

The regioselective cyclometalation reactions of 2-alkenylpyridine/-pyrazine derivatives with Co(CH3)(PMe3)4 provide cobalt complexes by vinylic C(sp2)–H activation. These cobalt complexes smoothly add iodomethane but readily demetalate with carbon monoxide. Conversely, reductive elimination through the release of ethane is the dominant reaction with the same ligands and Fe(CH3)2(PMe3)4.

Eur. J. Inorg. Chem. 2015, No. 15, 2543-2559

Leung Gulice Yiu Chung, Nur Asyikin Binte Juwaini, Jayasree Seayad
Palladium-Catalyzed Oxidative Heck Coupling of Cyclic Enones with Simple Arenes by C-H Activation [Communication]

Palladium-Catalyzed Oxidative Heck Coupling of Cyclic Enones with Simple Arenes by C-H Activation

For the Heck of it: A simple catalyst system consisting of Pd(OAc)2 and 3-nitropyridine for the aerobic oxidative Heck coupling of challenging unsubstituted cyclic enones with simple arenes by C-H activation is reported. This method is applicable to various substituted arenes and cyclic enones and allows the synthesis of a range of β-aryl cyclic enones.

ChemCatChem 2015, 7, No. 08, 1270-1274

Neeraj Kumar Mishra, Taejoo Jeong, Satyasheel Sharma, Youngmi Shin, Sangil Han, Jihye Park, Joa Sub Oh, Jong Hwan Kwak, Young Hoon Jung, In Su Kim
Rhodium(III)-Catalyzed Selective C-H Cyanation of Indolines and Indoles with an Easily Accessible Cyano Source [Update]

Gang Li, Chunqi Jia, Qingliang Chen, Kai Sun, Feng Zhao, Hankui Wu, Zhiyong Wang, Yunhe Lv, Xiaolan Chen
Copper(I)-Catalyzed Dehydrogenative Amidation of Arenes Using Air as the Oxidant [Update]

Pd-Catalyzed C-H Activation: Expanding the Portfolio of Metal-Catalyzed Functionalization of Unreactive C-H Bonds by Arene–Chromium π-Complexation

Switch it on: η6-arene–transition-metal complexes are significant intermediates in organic chemistry; however, their use in C-H functionalization remain largely unexplored. Recently, new methodologies for the Pd-catalyzed C-H activation of unreactive sp2 and sp3 bonds that rely on the efficient activation of arenes by π-complexation have been developed. These reactions significantly expand the toolbox of modern C-H activation methods.

ChemCatChem 2015, 7, No. 07, 1061-1063

Transition-Metal-Catalyzed π-Bond-Assisted C-H Bond Functionalization: An Emerging Trend in Organic Synthesis

Piece of pi: Transition-metal-catalyzed directing-group-assisted C-H activation reactions play an indispensable role in organic synthesis. Most directing groups interact with metals through the σ coordination of their lone pairs, yet π-bond directing groups also exist (see figure). The π-coordination-assisted C-H bond functionalization reactions are summarized.

Chem. Asian J. 2015, 10, No. 04, 824-838

Cp*CoIII-Catalyzed C-H Activation of (Hetero)arenes: Expanding the Scope of Base-Metal-Catalyzed C-H Functionalizations

Directed activation: Cationic Cp*CoIII (Cp*=1,2,3,4,5-pentamethylcyclopentadienyl) complexes, either well-defined or in situ-generated, promote catalytic functionalization of arene C-H bonds with a variety of electrophilic reaction partners by directed C-H activation. These complexes not only emulate known reaction patterns of Cp*RhIII analogues, but also exhibit remarkable catalytic activity or unique reactivity. DG=Directing group.

ChemCatChem 2015, 7, No. 05, 732-734

Youngmi Shin, Satyasheel Sharma, Neeraj Kumar Mishra, Sangil Han, Jihye Park, Hyunji Oh, Jimin Ha, Hyunwu Yoo, Young Hoon Jung, In Su Kim
Direct and Site-Selective Palladium-Catalyzed C-7 Acylation of Indolines with Aldehydes [Update]

Norbert Hoffmann
Combining Photoredox and Metal Catalysis [Highlight]

Combining Photoredox and Metal Catalysis

A photogenic pair: Photoredox catalysis with visible light and molecular oxygen as oxidant in combination with palladium catalysis enables highly efficient activation of C-H bonds. Mild photochemical reaction conditions generally facilitate the combination of different catalytic reactions.

ChemCatChem 2015, 7, No. 03, 393-394

Yasutomo Segawa, Takehisa Maekawa, Kenichiro Itami
Synthesis of Extended π-Systems through C–H Activation [Review]

Synthesis of Extended π-Systems through C–H Activation

By no means π in the sky! The activation of aromatic C-H bonds by a transition metal catalyst has received significant attention in the synthetic chemistry community. In recent years, rapid and site-selective extension of π-electron systems by C–H activation has emerged as an ideal methodology for preparing conjugated organic materials. This Review focuses on recent developments in this area directed toward new optoelectronic materials.

Angew. Chem. Int. Ed. 2015, 54, No. 01, 66-81

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 2015, 7, No. 02, 223-225

Malek Nechab, Shovan Mondal, Michèle P. Bertrand
1,n-Hydrogen-Atom Transfer (HAT) Reactions in Which n≠5: An Updated Inventory [Review]

1,n-Hydrogen-Atom Transfer (HAT) Reactions in Which n≠5: An Updated Inventory

Intramolecular HAT scope: The investigation of the less commonly encountered 1,n-hydrogen-atom transfer (HAT) reactions in which n≠5 has led to high yielding original synthetic applications. The aim of this Review is to make a critical updated inventory, highlighting the most elegant cascade reactions based on a 1,n-HAT elementary step (from A to B) in which n=4, 6, 7, 8, 9, and so forth.

Chem. Eur. J. 2014, 20, No. 49, 16034-16059

Matthijs Ruitenbeek, Bert M. Weckhuysen
A Radical Twist to the Versatile Behavior of Iron in Selective Methane Activation [Highlight]

A Radical Twist to the Versatile Behavior of Iron in Selective Methane Activation

Things go better without coke! The selective activation of methane and its direct conversion into light olefins and aromatic compounds remains a formidable challenge. Recent work shows that a catalyst material consisting of lattice-confined single iron atoms is very active and selective in the direct, nonoxidative conversion of methane into ethylene, benzene, and naphthalene without the formation of coke deposits.

Angew. Chem. Int. Ed. 2014, 53, No. 42, 11137-11139

Niles J. Gunsalus, Michael M. Konnick, Brian G. Hashiguchi, Roy A. Periana
Discrete Molecular Catalysts for Methane Functionalization [Review]

Rowan D. Young
Characterisation of Alkane σ-Complexes [Minireview]

Characterisation of Alkane σ-Complexes

The coordination of alkanes to metal centers is a complex matter! Advances in synthetic strategies to produce alkane σ-complexes, and ever more detailed analyses of such complexes, is leading to an understanding of how alkanes bind to specific metal centers. Such analysis is vital in understanding selectivity in C-H activation reactions.

Chem. Eur. J. 2014, 20, No. 40, 12704-12718

Johannes Schranck, Anis Tlili, Matthias Beller
Functionalization of Remote C-H Bonds: Expanding the Frontier [Highlight]

Functionalization of Remote C-H Bonds: Expanding the Frontier

Novel tool set: New methodologies for the functionalization of remote C-H bonds have been developed recently. In diverse approaches high selectivities are achieved for the functionalization of less reactive C(sp2)-H as well as C(sp3)-H bonds distal to any substituents.

Angew. Chem. Int. Ed. 2014, 53, No. 36, 9426-9428

Frédéric Liron, Julie Oble, Mélanie M. Lorion, Giovanni Poli
Direct Allylic Functionalization Through Pd-Catalyzed C–H Activation [Microreview]

Direct Allylic Functionalization Through Pd-Catalyzed C–H Activation

This review outlines some selected examples and present challenges relating to palladium-catalyzed direct allylic functionalization. This old reaction, ignored for many years, is enjoying a new age.

Eur. J. Org. Chem. 2014, No. 27, 5863-5883

Laurent Djakovitch, François-Xavier Felpin
Direct C sp2-H and C sp3-H Arylation Enabled by Heterogeneous Palladium Catalysts [Minireview]

Direct C sp2-H and C sp3-H Arylation Enabled by Heterogeneous Palladium Catalysts

When palladium meets a support: The functionalization of the C-H bond is the most straightforward approach to create new bonds. Although most studies involve homogeneous transition-metal catalysts, in this Minireview we aim to give a picture of recent advances of direct C-H arylations enabled by heterogeneous Pd catalysts.

ChemCatChem 2014, 6, No. 08, 2175-2187

Jamal Koubachi, Saïd El Kazzouli, Mosto Bousmina, Gérald Guillaumet
Functionalization of Imidazo[1,2-a]pyridines by Means of Metal-Catalyzed Cross-Coupling Reactions [Microreview]

Functionalization of Imidazo[1,2-a]pyridines by Means of Metal-Catalyzed Cross-Coupling Reactions

The latest developments in the field of imidazo[1,2-a]pyridine functionalization by means of cross-coupling reactions such as the Sonogashira, Heck, Negishi, Suzuki–Miyaura, and Stille reactions, as well as by C-arylation, C-alkenylation, carbonylation, and double functionalization, are reviewed and discussed.

Eur. J. Org. Chem. 2014, No. 24, 5119-5138

Ligands Control Reactivity and Selectivity in Palladium-Catalyzed Functionalization of Unactivated C sp3-H Bonds

Ligands at the wheel: The pivotal role of ligands for the palladium-catalyzed functionalization of remote C sp3-H bonds has been demonstrated. The presence of the ligand enhances the reactivity of the inert C sp3-H bond and controls the selectivity of the process. DG=Directing group, FG=functional group.

ChemCatChem 2014, 6, No. 08, 2188-2190

Direct Functionalization with Complete and Switchable Positional Control: Free Phenol as a Role Model

PhenAll: Recent breakthroughs in site-selective and direct functionalization of free phenols by transition-metal-catalyzed C-O or C-H bond activation are highlighted here as role models for the complete and switchable positional control of transformations of important core structures.

Angew. Chem. Int. Ed. 2014, 53, No. 30, 7710-7712

Yan Li, Yun Wu, Guang-Shui Li, Xi-Sheng Wang
Palladium-Catalyzed C-F Bond Formation via Directed C-H Activation [Review]

Christoph Kornhaaß, Christian Kuper, Lutz Ackermann
Ferrocenylalkynes for Ruthenium-Catalyzed Isohypsic C-H/N-O Bond Functionalizations [Update]

Suman De Sarkar, Weiping Liu, Sergei I. Kozhushkov, Lutz Ackermann
Weakly Coordinating Directing Groups for Ruthenium(II)- Catalyzed C-H Activation [Review]

Zhao-Lei Yan, Wen-Liang Chen, Ya-Ru Gao, Shuai Mao, Yan-Lei Zhang, Yong-Qiang Wang
Palladium-Catalyzed Intermolecular C-2 Alkenylation of Indoles Using Oxygen as the Oxidant [Update]

José Luis García Ruano, José Alemán, Alejandro Parra, Leyre Marzo
Sulfonyl Acetylenes as Alkynylating Reagents Under Radical or Anionic Conditions [Microreview]

Sulfonyl Acetylenes as Alkynylating Reagents Under Radical or Anionic Conditions

We summarize a powerful methodology for the alkynylation of C(sp3), C(sp2), and C(sp) carbon atoms, as well as some heteroatoms, with alkynylsulfones. It is based on the fact that β-substituted sulfonylacetylenes undergo unexpected anti-Michael addition of organolithiums and radical species, giving intermediates that evolve into alkynyl derivatives in situ by elimination of the anion or radical TolSO2.

Eur. J. Org. Chem. 2014, No. 08, 1577-1588

Philipp J. Gritsch, Christian Leitner, Magnus Pfaffenbach, Tanja Gaich
The Witkop Cyclization: A Photoinduced C-H Activation of the Indole System [Minireview]

The Witkop Cyclization: A Photoinduced C-H Activation of the Indole System

To wit: The title reaction resembles a photoinduced electron-transfer process, and allows the direct formation of medium-sized lactams by C-H activation of the indole nucleus. Therefore it is a versatile tool for the construction of polycyclic indole alkaloid scaffolds.

Angew. Chem. Int. Ed. 2014, 53, No. 05, 1208-1217

Towards Ideal Synthesis: Alkenylation of Aryl C-H Bonds by a Fujiwara–Moritani Reaction

Chemical power tools: The Fujiwara–Moritani reaction is the palladium-catalyzed coupling reaction of a simple aryl C-H bond with an alkenyl C-H bond to form a new C-C bond (see scheme). This Minireview focuses on the advances in the past five years related to the activation of various aryl C-H bonds in this coupling reaction.

Chem. Eur. J. 2014, 20, No. 03, 634-642

The Cross-Dehydrogenative Coupling of Csp3-H Bonds: A Versatile Strategy for C-C Bond Formations

Waste not, want not: The title CDC reactions have emerged as versatile tools for selective and waste-minimized C-C bond formations. They rely on the direct coupling of two different C-H bonds under oxidative conditions. This Review focuses on the recent progress in cross-dehydrogenative Csp3-C formation and provides a comprehensive overview on existing procedures and employed methodologies.

Angew. Chem. Int. Ed. 2014, 53, No. 01, 74-100

Yinuo Wu, Jun Wang, Fei Mao, Fuk Yee Kwong
Palladium-Catalyzed Cross-Dehydrogenative Functionalization of C(sp2)-H Bonds [Focus Review]

Palladium-Catalyzed Cross-Dehydrogenative Functionalization of C(sp2)-H Bonds

Caught in the cross-fire: This Review highlights the recent developments in catalytic cross-dehydrogenative coupling (CDC) reactions, which join together two aromatic C-H fragments through a palladium-catalyzed dehydrogenative pathway.

Chem. Asian J. 2014, 9, No. 01, 26-47

New Site-Selective Organoradical Based on Hypervalent Iodine Reagent for Controlled Alkane sp3 C-H Oxidations

Large Iodine: The site-selective oxidation of unactivated secondary sp3 C-H bonds was accomplished by using a newly defined reactive hypervalent iodine(III) radical in the presence of tert-butyl hydroperoxide (see scheme). Recent studies on hypervalent iodine radicals have significantly contributed to the further development and design of organic molecules in radical oxidation chemistry.

ChemCatChem 2014, 6, No. 01, 76-78

© Wiley-VCH 2013.