Highly enantioselective synthesis of γ-substituted butenolides via the vinylogous Mukaiyama–Michael reaction catalyzed by a chiral scandium(iii)–N,N′-dioxide complex
作者:Qi Zhang、Xiao Xiao、Lili Lin、Xiaohua Liu、Xiaoming Feng
DOI:10.1039/c1ob05558e
日期:——
A highly efficient catalytic asymmetric vinylogous Mukaiyama–Michael reaction of the 2-silyloxyfuran with chalcone derivatives, catalyzed by a chiral N,N′-dioxide–scandium(III) complex, has been accomplished which tolerates a wide range of substrates. The reaction proceeds with complete regioselectivities, excellent diastereoselectivities (up to >99 : 1 dr) and good to excellent enantioselectivities
2-手性N,N'-二氧化物-scan(III)配合物催化的2-甲硅烷基呋喃与查尔酮衍生物的高效催化不对称乙烯基类化合物的Mukaiyama-Michael反应已经完成,可耐受多种底物。在温和条件下,反应以完全的区域选择性,优异的非对映选择性(最高> 99:1 dr)和良好至优异的对映选择性(最高94%ee)进行,可提供高度官能化的对映异构体富集的抗-γ-取代的丁烯内酯。该过程是耐空气的,并且可以使用现有的试剂轻松地进行操作。为了说明该反应的合成潜力,已研究了克级合成和丁烯内酯的精制。根据实验结果,提出了可能的催化循环和良好的立体识别模型。