Catalytic Asymmetric Protonation of Silyl Ketene Imines
摘要:
An efficient catalytic and highly enantioselective protonation of silyl ketene imines is described. The reaction is catalyzed by the chiral phosphoric acids TRIP or STRIP in the presence of a stoichiometric amount of methanol as the proton source and silyl acceptor. A variety of substituted racemic silyl ketene imines have been transformed into highly enantioenriched nitriles.
A cyanide‐free platform technology for the synthesis of chiral nitriles by biocatalytic enantioselective dehydration of a wide range of aldoximes is reported. The nitriles were obtained with high enantiomeric excess of >90 % ee (and up to 99 % ee) in many cases, and a “privileged substrate structure” with respect to high enantioselectivity was identified. Furthermore, a surprising phenomenon was observed
reaction conditions for radical decarboxylation to produce alkyl radicals, which could be effectively intercepted by asymmetric electrochemical Cu catalysis for the construction of C−CN bonds in a highly stereoselective manner.
开发了一种可持续且高效的电光化学金属催化方案,用于将现成的脂肪族羧酸直接转化为手性烷基腈。电光化学 Ce 催化能够在温和的反应条件下自由基脱羧产生烷基自由基,其可以被不对称电化学 Cu 催化有效拦截,以高度立体选择性的方式构建 C-CN 键。