Article
Chemistry, Multidisciplinary
Xiaoqiang Yan, Jijun Jiang, Jun Wang
Summary: In this study, an unusual class of planar-chiral rhodium catalysts bearing non-chiral Cp ligands was described. These catalysts are readily tunable and were successfully used in enantioselective C-H activation reactions, showing great potential in this field.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Xin-Meng Chen, Ling Zhu, Dian-Feng Chen, Liu-Zhu Gong
Summary: The chiral indoline-2-carboxylic acid enables a highly enantioselective Catellani-type annulation, directly assembling a diverse range of chiral all-carbon bridged ring systems with high levels of stereochemical control through coordinating orientation to the arylpalladium(II) center identified by control experiments and DFT calculations.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Physical
Yoshimi Kato, Luqing Lin, Masahiro Kojima, Tatsuhiko Yoshino, Shigeki Matsunaga
Summary: By introducing pseudo-C2 symmetric tunable chiral carboxylic acids, the study achieved enantioselective C(sp(3))-H amidation reactions of substrates such as 2-alkylpyridines, improving the chiral selectivity towards the substrates.
Article
Chemistry, Physical
Ouidad Lahtigui, Dan Forster, Coralie Duchemin, Nicolai Cramer
Summary: In this study, a flexible two-step protocol for the efficient and selective synthesis of rigid saturated nitrogen-containing scaffolds was disclosed. The method involves alkenyl C-H functionalization and cyclization reactions mediated by C*Rh-III and Cp*Ir-III catalysts, respectively, leading to the synthesis of diverse substituted 3-azabicyclo[3.1.0]hexanes.
Article
Chemistry, Organic
Ayumi Inami, Yuji Nishii, Koji Hirano, Masahiro Miura
Summary: In this study, a new synthetic method was developed using vinyl selenone as a surrogate for phenylacetylene in the Rh-catalyzed annulative coupling reaction. This method successfully produced 3,4-nonsubstituted isoquinoline compounds. The reaction conditions were mild and the vinyl selenone could be recovered and recycled.
Review
Chemistry, Multidisciplinary
Oleksandr Vyhivskyi, Anton Kudashev, Takeru Miyakoshi, Olivier Baudoin
Summary: Processes involving transition-metal catalysis have become a major part of synthetic chemists' toolbox in recent decades. The focus has shifted from cross-coupling reactions to C-H bond functionalization, with constant progress leading to discovery of enantioselective methods. The review discusses enantioselective Pd-0-catalyzed C-H activation, highlighting the importance of different chiral ligands and catalysts in enabling these transformations.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Physical
Tatsuhiko Yoshino, Shigeki Matsunaga
Summary: Enantioselective C-H functionalization is a powerful tool for synthesizing chiral molecules. The combination of high-valent group 9 metals with achiral Cp-x ligands and chiral carboxylic acids has shown promise in enabling selective cleavage and functionalization of enantiotopic C-H bonds. This Perspective provides a detailed summary of the background, catalyst design, applied reactions, and future directions in this field.
Article
Chemistry, Organic
Yang An, Xiao-Yan Zhang, Ya-Nan Ding, Yuke Li, Xue-Yuan Liu, Yong-Min Liang
Summary: This study synthesized ferrocenes with planar chirality using palladium/chiral norbornene cooperative catalysis and axial-to-planar diastereoinduction. The chiral norbornene was used to control the aromatic axial chirality and induce the planar chirality of ferrocene through C(sp2)-H activation.
Article
Chemistry, Inorganic & Nuclear
Kristina Zivkovic, Lilia M. Baldauf, Jessica L. Cryder, Alexa Villasenor, Valeria Reyes, Lauren E. Bernier, Theresa J. Thomas, Maxwell O'Toole, Kayleen Fulton, Curtis E. Moore, Arnold L. Rheingold, Christopher J. A. Daley
Summary: The study reports the first isolation and structural characterization of a series of chiral trinitrogen pincer ligands, as well as the methods for their preparation. Experimental results show that a novel microwave-based technique is more efficient, although currently not scalable.
DALTON TRANSACTIONS
(2021)
Article
Chemistry, Physical
Hui Yang, Ru Zhang, Su-Zhen Zhang, Qing Gu, Shu-Li You
Summary: Researchers have developed a series of chiral spiro ligands (BCSCp) from commercially available and cheap Bisphenol C, and prepared their corresponding rhodium complexes. These complexes have been successfully applied in enantioselective aryl C-H addition to nitroalkenes, producing C-H adducts with yields up to 88% and ee up to 98%.
Article
Chemistry, Organic
Ruxia Mao, Yanliang Zhao, Xiaohan Zhu, Fen Wang, Wei-Qiao Deng, Xingwei Li
Summary: In this study, enantioenriched allenes were successfully obtained through Rhodium(III)-catalyzed C-H allenylation of tertiary propargyl alcohols. The reaction proceeded efficiently under mild conditions, resulting in high enantioselectivities for both the allenylated products and propargyl alcohols. The resolution was achieved through bias of the propargylic substituents and assistance of a chiral zinc carboxylate additive.
Article
Chemistry, Multidisciplinary
Shuaishuai Song, Yunfei Lai, Zekun Tuo, Jianming Zhong, Wang Zhou
Summary: A rhodium(III)-catalyzed oxidative cyclization of chalcones with internal alkynes is reported, resulting in the formation of biologically important 3,3-disubstituted 1-indanones and reusable aromatic aldehydes. This transformation exhibits a unique (4+1) reaction mode, excellent regioselectivity, broad substrate scope, ability to construct quaternary carbon centers, and scalability. Steric hindrance from the substrate and ligand likely controls the chemoselectivity of this carbocyclization. Importantly, this discovery enables a practical two-step protocol to switch the overall reaction from a (3+2) to a (4+1) annulation of acetophenones with internal alkynes.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Fen Wang, Jierui Jing, Yanliang Zhao, Xiaohan Zhu, Xue-Peng Zhang, Liujie Zhao, Panjie Hu, Wei-Qiao Deng, Xingwei Li
Summary: This paper describes an asymmetric [3+2] annulation reaction of arylnitrones with different classes of alkynes catalyzed by chiral rhodium(III) complexes, resulting in the construction of three classes of chiral indenes/indenones. The coupling system features mild reaction conditions, excellent enantioselectivity, and high atom-economy, producing atropochiral pentatomic biaryls with C-centered point-chirality in excellent enantio- and diastereoselectivity.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Wen-Wen Zhang, Qiang Wang, Su-Zhen Zhang, Chao Zheng, Shu-Li You
Summary: Satoh-Miura reaction is an important method for extending pi-systems via C-H activation and alkynyl annulation. However, achieving high enantioselectivity remains challenging. In this study, an asymmetric Satoh-Miura reaction using a SCpRh-catalyst is reported, and it is found that choosing the counteranion of the catalyst is crucial for the desired reactivity.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Organic
Qi-Liang Yang, Yi-Rui Luo, Rong-Yi Xu, Bei-Ning Zhang, Yan-Ni Zhang, Hai-Ming Guo
Summary: A sustainable pathway for the synthesis of tetracyclic purinium salts via ruthenium-catalyzed electro-oxidative annulation of C-6-arylpurine nucleosides with alkynes without a stoichiometric metal oxidant has been developed. The protocol exhibits high regioselectivity, broad scope, and wide functional group tolerance, allowing efficient coupling of various biologically important molecules. A novel purinoisoquinolinium-coordinated ruthenium(0) sandwich intermediate has been isolated, crystallographically characterized, and electrochemically analyzed, offering direct mechanistic insight.
Review
Chemistry, Multidisciplinary
Josep Mas-Rosello, Ana G. Herraiz, Benoit Audic, Aragorn Laverny, Nicolai Cramer
Summary: The development of new chiral ligands is crucial for stereocontrol in metal-catalyzed reactions, especially with the increasing demand for bioactive molecules as single enantiomers. The successful application of Cp-X ligands in metal-catalyzed transformations allows access to valuable chiral molecules, with critical comparisons of existing ligand families and discussion of future research directions for further enhancing their performance and application in enantioselective catalysis.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Kristers Ozols, Shunsuke Onodera, Lukasz Wozniak, Nicolai Cramer
Summary: The study presents a method for highly enantioselective intermolecular carboaminations of alkenes through C-H activation catalyzed by high-valent cyclopentadienyl cobalt complexes. This method converts widely available acrylates and bicyclic olefins into enantioenriched isotyrosine derivatives and amino-substituted bicyclic scaffolds under very mild conditions. The reactivity outlined in this research is unique to the (CpCoIII)-Co-x complexes and complements the reactivity of 4d- and 5d- precious-metal catalysts.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Lukasz Wozniak, Nicolai Cramer
Summary: Atropo-enantioselective biaryl coupling through C-H bond functionalization is an emerging technology allowing direct construction of axially chiral molecules. This highly enantioselective C-H arylation reaction utilizes chiral cyclopentadienyl iridium complexes as catalysts, paired with aryl boronic esters as nucleophilic components, enabled by oxidatively enhanced reductive elimination from high-valent cyclometalated Ir-species.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Physical
Ana G. Herraiz, Nicolai Cramer
Summary: Catalytic enantioselective C-H functionalization has become a tool for creating stereogenic centers, but remains a challenge. A three-component C-H functionalization catalyzed by an earth-abundant Co(III) complex with high enantioselectivity has been described, providing a rapid access to substituted beta-hydroxyketones. The outlined reactivity of (CpCo)-Co-x(III) catalysis shows a higher and exploitable propensity for selective additions across carbonyls compared to Rh(III) chemistry.
Article
Chemistry, Multidisciplinary
Elena Braconi, Nicolai Cramer
Summary: The study presents an iron-catalyzed reaction that allows the synthesis of chiral 1,3-substituted vinylcyclohexenes from unactivated dienes. By developing specific ligands, high reactivity and selectivity are achieved, suitable for a variety of diene substrates.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Review
Chemistry, Multidisciplinary
Josep Mas-Rosello, Nicolai Cramer
Summary: Catalytic reduction of oximes is an efficient method for synthesizing valuable hydroxylamine derivatives, but faces challenges such as the difficulty of reducing oximes and the complexity of their reactivity. Recent developments have focused on metal-free and transition-metal-based homogeneous catalysts with higher turnovers, yet issues with stereoselectivity and substrate preparation remain to be addressed.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Jin-Fay Tan, Carl Thomas Bormann, Kay Severin, Nicolai Cramer
Summary: This study developed a mild and operationally simple perfluorination method, converting 1-alkynyl triazenes into 1,1,2,2-tetrafluoro alkyl triazenes, while also obtaining alpha-difluoro triazenyl ketones and alpha-difluoro acyl triazenes. These methods expand the chemical space for these unusual entities.
Correction
Chemistry, Physical
Ana G. Herraiz, Nicolai Cramer
Article
Chemistry, Multidisciplinary
Johannes Klett, Lukasz Wozniak, Nicolai Cramer
Summary: 1,3,2-Diazaphospholenes hydrides (DAP-Hs) are highly nucleophilic organic hydrides that serve as main-group catalysts for a wide range of transformations, including a reductive radical cyclization of aryl and alkyl halides. Under mild conditions, the DAP catalyst undergoes a turnover process through a sigma-bond metathesis reaction with HBpin, and visible light irradiation accelerates the reaction. Mechanistic investigations suggest that visible light leads to the formation of DAP dimers, which accelerate the cyclization reaction.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Matthew D. Wodrich, Miyeon Chang, Simone Gallarati, Lukasz Wozniak, Nicolai Cramer, Clemence Corminboeuf
Summary: This study creates selectivity and activity maps by analyzing the catalyst-solvent interplay, which can be used to predict and optimize the outcome of competing reactions. The experimental results demonstrate that choosing the appropriate catalyst and solvent can simultaneously optimize catalytic activity and selectivity.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Physical
Ouidad Lahtigui, Dan Forster, Coralie Duchemin, Nicolai Cramer
Summary: In this study, a flexible two-step protocol for the efficient and selective synthesis of rigid saturated nitrogen-containing scaffolds was disclosed. The method involves alkenyl C-H functionalization and cyclization reactions mediated by C*Rh-III and Cp*Ir-III catalysts, respectively, leading to the synthesis of diverse substituted 3-azabicyclo[3.1.0]hexanes.
Article
Chemistry, Inorganic & Nuclear
Adrien Madron du Vigne, Nicolai Crame
Summary: Despite recent advances in the field of cyclic alkyl amino carbenes (CAACs), the application potential of chiral CAACs to efficiently catalyze asymmetric organometallic transformations remains largely underdeveloped. A convenient and robust route incorporating common chiral primary amine allows access to a broad range of chiral CAACs precursors, and the transition-metal complexes obtained in a straightforward manner can serve as a source of information for further ligand design.
Article
Chemistry, Multidisciplinary
Guoting Zhang, Nicolai Cramer
Summary: 1,3,2-diazaphospholene hydrides (DAP-H) are effective in reducing polarized double bonds. The transient formation of phosphorus-enolate provides a potential platform for reductive alpha-functionalizations. We report a three-step cascade reaction catalyzed by 1,3,2-diazaphospholene, involving conjugate reduction, [2,3]-sigmatropic aza-Mislow-Evans rearrangement, and subsequent S-O bond cleavage. The obtained enantio-enriched alpha-hydroxy amides show good yields and excellent enantiospecificity. The reaction operates under mild conditions at ambient temperature, and DAP-H can also cleave formed sulfenate ester, eliminating an extra step in traditional Mislow-Evans processes.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Matthew D. Wodrich, Ruben Laplaza, Nicolai Cramer, Markus Reiher, Clemence Corminboeuf
Summary: In this mini review, a computational pipeline developed in the framework of NCCR Catalysis is presented, which can successfully reproduce the enantiomeric ratios of homogeneous catalytic reactions. The pipeline is based on the SCINE Molassembler module, a graph-based software that provides molecular construction algorithms for all periodic table elements. With this pipeline, simultaneous functionalization and generation of ensembles of transition state conformers is possible, allowing exploration of the influence of various substituents on the overall enantiomeric ratio. This provides quick and reliable access to energetically low-lying transition states, which is crucial for in silico catalyst optimization.
Article
Chemistry, Multidisciplinary
Jin-Fay Tan, Carl Thomas Bormann, Kay Severin, Nicolai Cramer
Summary: The 2-pyrone motif in bioactive natural products can be modified through the properties of 1-alkynyl triazenes with the addition of propiolic acids and subsequent cyclization induced by silver salt. Different triazenyl derivatives of 2-pyrones can be selectively formed depending on reaction temperature and further replaced by various groups, leading to valuable compounds such as 2-fluoro pyrones. The triazenyl group also plays a role in subsequent Diels-Alder cycloadditions and in the formation of rare fused aminopyrazole pyrone heterocycles.
