A Neutral Metal-Free System for Head-to-Tail Dimerization of Electron-Rich Alkenes
作者:A-Yun Luo、Yan Bao、Xiu-Fen Cheng、Xi-Sheng Wang
DOI:10.1055/s-0036-1589039
日期:2017.9
Abstract A neutral metal-free system for the head-to-tail dimerization of electron-rich alkenes with stoichiometric amount of BrCCl2H and NaI is reported. This reaction proceeds under mild conditions with high efficiency and broad scope. A neutral metal-free system for the head-to-tail dimerization of electron-rich alkenes with stoichiometric amount of BrCCl2H and NaI is reported. This reaction proceeds
作者:Alesandere Ortega、Rubén Manzano、Uxue Uria、Luisa Carrillo、Efraim Reyes、Tomas Tejero、Pedro Merino、Jose L. Vicario
DOI:10.1002/anie.201804614
日期:2018.7.2
Racemic cyclopropyl ketones undergo enantioselectiverearrangement to deliver the corresponding dihydrofurans in the presence of a chiral phosphoric acid as the catalyst. The reaction involves activation of the donor‐acceptor cyclopropane substrate by the chiral Brønsted acid catalyst to promote the ring‐opening event, thus generating a carbocationic intermediate that subsequently undergoes cyclization
Enantioselective Hydroalkenylation of Olefins with Enol Sulfonates Enabled by Dual Copper Hydride and Palladium Catalysis
作者:Alexander W. Schuppe、James Levi Knippel、Gustavo M. Borrajo-Calleja、Stephen L. Buchwald
DOI:10.1021/jacs.1c02117
日期:2021.4.14
The catalytic enantioselective synthesis of α-chiral olefins represents a valuable strategy for rapid generation of structural diversity in divergent syntheses of complex targets. Herein, we report a protocol for the dual CuH- and Pd-catalyzed asymmetric Markovnikov hydroalkenylation of vinyl arenes and the anti-Markovnikov hydroalkenylation of unactivated olefins, in which readily available enol triflates
reagents (trifluoromethyl)(4-nitrophenyl)bis(carbomethoxy)methylide (1g) and (trifluoromethyl)(3-chlorophenyl)bis(carbomethoxy)methylide (1j) through structure-activity study was described. Under mild conditions, reagent 1g reacted with β-ketoesters and silyl enol ethers to give α-trifluoromethylated-β-ketoesters or α-trifluoromethylated ketones in high yields. In addition, reagent 1g could serve as
yields and excellent regio-, enantio-, and Z/E-selectivities. The utility of this transformation was demonstrated by a broad range of styrenes and 1,3-dienes, facile product modification, and synthesis of bioactive compounds (R)-(-)-curcumene and (S)-(+)-ibuprofen. Mechanistic studies demonstrated the carboxylation of phenylethylcopper complexes with CO2 as one key step.