Enantioselective synthesis of γ-tetrasubstituted nitrosulfonyl carboxylates and amides via<scp>l</scp>-tert-leucine-derived-squaramide catalyzed conjugate addition of nitrosulfones to acrylates and acrylamides
作者:Kalisankar Bera、Irishi N. N. Namboothiri
DOI:10.1039/c4ob00344f
日期:——
Michael addition of α-nitrosulfones to aryl- and alkyl acrylates and acrylamides proceeds in the presence of 5–10 mol% of an amino acid derived new organocatalyst to provide γ-tetrasubstituted γ-nitro-γ-sulfonyl carboxylates and amides in excellent yields and enantioselectivities. Scale-up of the reaction to multi-grams, convenient recovery of the catalyst and its recyclability without any drop in
在5-10 mol%氨基酸衍生的新型有机催化剂存在下,将α-硝基砜迈克尔加成到丙烯酸芳基和烷基酯和丙烯酰胺上,以优异的收率提供γ-四取代的γ-硝基-γ-磺酰基羧酸酯和酰胺。对映选择性。反应规模扩大至数克,催化剂的方便回收及其可回收性,而收率和选择性均不降低,是该方法的吸引人的特点。