Solvent‐Dependent Asymmetric Synthesis of Alkynyl and Monofluoroalkenyl Isoindolinones by CpRhIII‐Catalyzed C−H Activation DOI
Teng Li, Chao Zhou,

Xiaoqiang Yan

et al.

Angewandte Chemie International Edition, Journal Year: 2018, Volume and Issue: 57(15), P. 4048 - 4052

Published: March 7, 2018

Abstract The asymmetric synthesis of alkynyl and monofluoroalkenyl isoindolinones from N‐methoxy benzamides α,α‐difluoromethylene alkynes is enabled by C−H activation with a chiral CpRh III catalyst. Remarkably, product formation solvent‐dependent; are afforded in MeOH (up to 86 % yield, 99.6 ee ) whereas generated i PrCN 98:2 Z / E , 93 ). Mechanistic studies revealed allene ‐configured alkenyl rhodium species as reaction intermediates. latter transformed into the corresponding monofluoroalkene upon protonation system an alkyne unusual anti β‐F elimination system. Notably, kinetic resolution processes occur this reaction. Despite moderate enantiocontrol for allene, ‐monofluoroalkenyl were obtained good enantiopurities one or two sequential processes.

Language: Английский

Asymmetric Dearomatization of Naphthols via a Rh-Catalyzed C(sp2)–H Functionalization/Annulation Reaction DOI
Jun Zheng, Shaobo Wang, Chao Zheng

et al.

Journal of the American Chemical Society, Journal Year: 2015, Volume and Issue: 137(15), P. 4880 - 4883

Published: April 8, 2015

A Rh-catalyzed enantioselective dearomatization of 1-aryl-2-naphthols with internal alkynes via C-H functionalization reaction was achieved. In the presence a chiral Cp/Rh catalyst and combined oxidants Cu(OAc)2 air (oxygen), various highly enantioenriched spirocyclic enones bearing an all-carbon quaternary stereogenic center could be synthesized in 33-98% yields up to 97:3 er.

Language: Английский

Citations

320
General Enantioselective C−H Activation with Efficiently Tunable Cyclopentadienyl Ligands DOI
Zhi‐Jun Jia, Christian Merten, Rajesh Gontla

et al.

Angewandte Chemie International Edition, Journal Year: 2017, Volume and Issue: 56(9), P. 2429 - 2434

Published: Jan. 26, 2017

Abstract Cyclopentadienyl (Cp) ligands enable efficient steering of various transition‐metal‐catalyzed transformations, in particular enantioselective C−H activation. Currently only few chiral Cp are available. Therefore, a conceptually general approach to ligand discovery would be invaluable as it the applicable and efficiently rapidly vary tune their structures. Herein, we describe three‐step gram‐scale synthesis structurally diverse widely collection (JasCp ligands) with highly variable adjustable Their modular nature amenability rapid structure variation enabled for three Rh III ‐catalyzed activation reactions, including one unprecedented transformation. This novel should further transformations.

Language: Английский

Citations

311
Enantioselective C(sp3)–H Amidation of Thioamides Catalyzed by a CobaltIII/Chiral Carboxylic Acid Hybrid System DOI

Seiya Fukagawa,

Yoshimi Kato,

Ryō Tanaka

et al.

Angewandte Chemie International Edition, Journal Year: 2018, Volume and Issue: 58(4), P. 1153 - 1157

Published: Nov. 27, 2018

Abstract Recent advances in Cp x M III catalysis (M=Co, Rh, Ir) have enabled a variety of enantioselective C(sp 2 )−H functionalization reactions, but 3 is still largely unexplored. We describe an asymmetric amidation thioamides using achiral Co /chiral carboxylic acid hybrid catalytic system, which provides easy and straightforward access to chiral β‐amino thiocarbonyl carbonyl building blocks with quaternary carbon stereocenter.

Language: Английский

Citations

248
Cross‐Coupling of α‐Carbonyl Sulfoxonium Ylides with C−H Bonds DOI
Manuel Barday,

Christopher Janot,

Nathan R. Halcovitch

et al.

Angewandte Chemie International Edition, Journal Year: 2017, Volume and Issue: 56(42), P. 13117 - 13121

Published: Aug. 29, 2017

Abstract The functionalization of carbon–hydrogen bonds in non‐nucleophilic substrates using α‐carbonyl sulfoxonium ylides has not been so far investigated, despite the potential safety advantages that such reagents would provide over either diazo compounds or their situ precursors. Described herein are cross‐coupling reactions with C(sp 2 )−H arenes and heteroarenes presence a rhodium catalyst. reaction proceeds by succession C−H activation, migratory insertion ylide into carbon–metal bond, protodemetalation, last step being turnover‐limiting. method is applied to synthesis benz[c]acridines when allied an iridium‐catalyzed dehydrative cyclization.

Language: Английский

Citations

239
C–H bond functionalization based on metal carbene migratory insertion DOI
Fangdong Hu, Ying Xia, Chen Ma

et al.

Chemical Communications, Journal Year: 2015, Volume and Issue: 51(38), P. 7986 - 7995

Published: Jan. 1, 2015

C–H bond activation has been merged with carbene coupling to furnish a series of novel synthetic methodologies.

Language: Английский

Citations

235
Rhodium(III)‐Catalyzed Enantiotopic C−H Activation Enables Access to P‐Chiral Cyclic Phosphinamides DOI
Yang Sun, Nicolai Cramer

Angewandte Chemie International Edition, Journal Year: 2016, Volume and Issue: 56(1), P. 364 - 367

Published: Aug. 30, 2016

Abstract Compounds with stereogenic phosphorus atoms are frequently used as ligands for transition‐metal well organocatalysts. A direct catalytic enantioselective method the synthesis of P ‐chiral compounds from easily accessible diaryl phosphinamides is presented. The use rhodium(III) complexes equipped a suitable atropochiral cyclopentadienyl ligand shown to enable an enantiodetermining C−H activation step. Upon trapping alkynes, broad variety cyclic phosphorus(V) atom formed in high yields and enantioselectivities. Moreover, these can be reduced enantiospecifically phosphorus(III) compounds.

Language: Английский

Citations

232
Chiral Cyclopentadienyl Ligands: Design, Syntheses, and Applications in Asymmetric Catalysis DOI
Josep Mas‐Roselló, Ana G. Herraiz, B. Audic

et al.

Angewandte Chemie International Edition, Journal Year: 2020, Volume and Issue: 60(24), P. 13198 - 13224

Published: July 16, 2020

The creation of new chiral ligands capable providing high stereocontrol in metal-catalyzed reactions is crucial modern organic synthesis. production bioactive molecules as single enantiomers increasingly required, and asymmetric catalysis with metal complexes constitutes one the most efficient synthetic strategies to access optically active compounds. Herein we offer a historical overview on development derivatives ubiquitous cyclopentadienyl ligand (CpX ), detail their successful application broad range transformations. Those include functionalization challenging C-H bonds beyond, giving an extensive catalogue valuable molecules. A critical comparison existing families, design, synthesis, complexation different metals also provided. In addition, future research directions are discussed further enhance performance CpX enantioselective catalysis.

Language: Английский

Citations

230
Transition Metal Catalyzed Enantioselective C(sp2)–H Bond Functionalization DOI
Tapas Kumar Achar,

Sudip Maiti,

Sadhan Jana

et al.

ACS Catalysis, Journal Year: 2020, Volume and Issue: 10(23), P. 13748 - 13793

Published: Nov. 12, 2020

Direct catalytic transformation of C–H bonds to new functionalities has provided a powerful strategy synthesize complex molecular scaffolds in straightforward way. Unstinting efforts the synthetic community have helped overcome long-standing major challenge regioselectivity by introducing directing group concept. However, full potential cannot be realized unless activated are stereochemically controlled. The enantioselective bond functionalization could provide an imperative tool for sustainable way synthesizing chiral scaffolds. Despite intrinsic challenges achieving stereocontrol, developed different tools order achieve stereoselective functionalization. In this review, we discuss remarkable recent advances emerging area C(sp2)–H highlight and opportunities, emphasizing techniques so far.

Language: Английский

Citations

221
Rhodium(III)-Catalyzed C–C Bond Formation of Quinoline N-Oxides at the C-8 Position under Mild Conditions DOI
Jisu Jeong, Pitambar Patel,

Heejun Hwang

et al.

Organic Letters, Journal Year: 2014, Volume and Issue: 16(17), P. 4598 - 4601

Published: Aug. 20, 2014

The Rh(III)-catalyzed C-8 selective direct alkylation and alkynylation of quinoline N-oxides has been developed. reactions proceeded highly efficiently at room temperature over a broad range substrates with excellent regioselectivity functional group tolerance. This development demonstrates the synthetic utility N-oxide directing as stepping stone for remote C–H functionalization quinolines.

Language: Английский

Citations

220
Asymmetric Catalysis Powered by Chiral Cyclopentadienyl Ligands DOI
Christopher G. Newton, David Kossler, Nicolai Cramer

et al.

Journal of the American Chemical Society, Journal Year: 2016, Volume and Issue: 138(12), P. 3935 - 3941

Published: Feb. 10, 2016

Application of chiral derivatives the versatile and ubiquitous cyclopentadienyl ligand has long remained an underdeveloped area in asymmetric catalysis. In this Perspective we highlight recent exciting results that demonstrate their enormous potential. particular, provide a comparative analysis available families, overview complexation chemistry, examination application catalytic enantioselective reactions. We also discuss current limitations speculate on developments are necessary to advance field further.

Language: Английский

Citations

220