Difluoroalkylation of Tertiary Amides and Lactams by an Iridium-Catalyzed Reductive Reformatsky Reaction
作者:Phillip Biallas、Ken Yamazaki、Darren J. Dixon
DOI:10.1021/acs.orglett.2c00438
日期:2022.3.18
An iridium-catalyzed, reductive alkylation of abundant tertiary lactams and amidesusing 1–2 mol % of Vaska’s complex (IrCl(CO)(PPh3)2), tetramethyldisiloxane (TMDS), and difluoro-Reformatsky reagents (BrZnCF2R) for the general synthesis of medicinally relevant α-difluoroalkylated tertiary amines is described. A broad scope (46 examples), including N-aryl- and N-heteroaryl-substituted lactams, demonstrated
A versatile and practical methodology to access beta amino and beta-hydroxy alpha,alpha-difluoro carbonyl compounds using indium metal is described. This methodology has been successfully applied to a broad range of substrates including aldehydes, ketones, and imines, affording the corresponding and highly valuable gem-difluoto esters. The wide substrate scope highlights the chemoselectivity of the process.
Kinetic resolution of 2,2-difluoro-3-hydroxy-3-aryl-propionates catalyzed by organocatalyst (R)-benzotetramisole
作者:Hui Zhou、Qing Xu、Peiran Chen
DOI:10.1016/j.tet.2008.04.055
日期:2008.6
Kinetic resolution of a series of ethyl 2,2-difluoro-3-hydroxy-3-aryl-propionates catalyzed by (R)-benzotetramisole has been performed. It was found that when the aryl group was phenyl or phenyl substituted with electron-donating group (such as -Me, -OMe, and -SMe) or naphthyl groups, the enantio-selectivity factor (s) could reach 20 or higher; electron-withdrawing (such as fluorine) substitution on the benzene ring dramatically lowers the s value. Kinetic resolution in preparative scale for some of the substrates demonstrated the applicability of this method. (c) 2008 Elsevier Ltd. All rights reserved.