Stereoselective thio-Michael addition to chalcones in water catalyzed by bovine serum albumin
作者:Nicoletta Gaggero、Domenico Carlo Maria Albanese、Giuseppe Celentano、Stefano Banfi、Alice Aresi
DOI:10.1016/j.tetasy.2011.06.024
日期:2011.6
A biomimetic, inexpensive, and simple method for the stereoselective thio-Michael addition of thiols to chalcones has been developed using bovine serum albumin (BSA) as a catalyst. Optically active products are obtained in high yield and with enantiomeric excesses of up to 70%. (C) 2011 Elsevier Ltd. All rights reserved.
Sc(III)-Catalyzed Enantioselective Addition of Thiols to α,β-Unsaturated Ketones in Neutral Water
This report concerns Lewis acid catalyzed enantioselective sulfa-Michael addition in neutral water by using a very efficient Sc(OTf)(3)/bipyridine 1 catalytic system. It is noteworthy that the protocol presented employs water as a reaction medium and allows us to obtain very high stereoselectivity and satisfactory yields for beta-keto sulphides deriving from aliphatic thiols. The recovery and reuse of both the aqueous medium and the catalytic system is also reported.
Organocatalytic Enantioselective Sulfa-Michael Additions to α,β-Unsaturated Diazoketones
作者:Patricia B. Momo、Eduardo F. Mizobuchi、Radell Echemendía、Isabel Baddeley、Matthew N. Grayson、Antonio C. B. Burtoloso
DOI:10.1021/acs.joc.1c03045
日期:2022.3.4
Enantioselective sulfa-Michael additions to α,β unsaturated diazocarbonyl compounds have been developed. Quinine-derived squaramide was found to be the best catalyst to promote C–S bond formation in a highly stereoselective fashion for alkyl and aryl thiols. The easy-to-follow protocol allowed the preparation of 22 examples in enantiomeric ratios up to 97:3 and reaction yields up to 94%. The mechanism