Uniting C1-Ammonium Enolates and Transition Metal Electrophiles via Cooperative Catalysis: The Direct Asymmetric α-Allylation of Aryl Acetic Acid Esters
作者:Kevin J. Schwarz、Jessica L. Amos、J. Cullen Klein、Dung T. Do、Thomas N. Snaddon
DOI:10.1021/jacs.6b01694
日期:2016.4.27
constitutes a significant challenge in the area of asymmetric catalysis, particularly where the configurational integrity of the products is problematic. Through the unprecedented merger of two independent, yet complementary, catalysis events it has been possible to facilitate the direct asymmetric α-allylation of readily available aryl aceticacid esters. Since enantioselection is determined by the nucleophile
The synergistic merger of a thiazolium N-heterocyclic carbene (NHC) catalyst and a palladium–bisphosphine catalyst enabled the allylation of aldehydeacylanions using allylic carbonates as electro...
Synergistic Cu/Pd Catalysis for Enantioselective Allylation of Ketimine Esters: The Direct Synthesis of α-Substituted α-Amino Acids and 2<i>H-</i>
Pyrrols
作者:Liang Wei、Lu Xiao、Chun-Jiang Wang
DOI:10.1002/adsc.201800986
日期:2018.12.21
An efficient synergistic Cu/Pd catalyzed enantioselective α‐allylation of acyclic ketimine esters has been reported, which provides an entry to nonproteinogenic α‐allyl α‐amino acids in high yield, exclusive regioselectivity, and excellent enantioselectivity. Moreover, the more challenging cyclic ketimine ester could also be employed as a nucleophile for the construction of 3,4‐dihydro‐2H‐pyrrole derivatives
Iridium-catalyzed enantioselective direct vinylogous allylic alkylation of coumarins
作者:Rahul Sarkar、Sankash Mitra、Santanu Mukherjee
DOI:10.1039/c8sc02041h
日期:——
first iridium-catalyzed enantioselective vinylogous allylicalkylation of coumarins is presented. Using easily accessible linear allylic carbonates as the allylic electrophile, this reaction installs unfunctionalized allyl groups at the γ-position of 4-methylcoumarins in an exclusively branched-selective manner generally in high yields with an excellent level of enantioselectivity (up to 99 : 1 er).
Allylic cross-coupling using aromatic aldehydes as α-alkoxyalkyl anions
作者:Akihiro Yuasa、Kazunori Nagao、Hirohisa Ohmiya
DOI:10.3762/bjoc.16.21
日期:——
allylic cross-coupling using aromatic aldehydes as α-alkoxyalkyl anions is described. The synergistic palladium/copper-catalyzed reaction of aromatic aldehydes, allylic carbonates, and a silylboronate produces the corresponding homoallylic alcohol derivatives. This process involves the catalytic formation of a nucleophilic α-silyloxybenzylcopper(I) species and the subsequent palladium-catalyzed allylic