Structure influence of chiral 1,1′-biscarboline-N,N′-dioxide on the enantioselective allylation of aldehydes with allyltrichlorosilanes
作者:Bing Bai、Hua-Jie Zhu、Wei Pan
DOI:10.1016/j.tet.2012.06.042
日期:2012.8
A series of new axially chiral 1,1′-biscarboline-N,N′-dioxide Lewis base organocatalysts were examined in the asymmetric allylation of aldehydes with allyltrichlorosilane. The chiral catalysts (R)-1a–e bearing ester groups in 3,3′ position provided good yields of the homoallyl alcohols with excellent enantioselectivities up to 99% for a broad substrate scope that covers aliphatic, aromatic, heteroaromatic
在醛与烯丙基三氯硅烷的不对称烯丙基化反应中,研究了一系列新型的轴向手性1,1'-双咔啉-N,N'-二氧化物路易斯碱有机催化剂。的手性催化剂([R )- 1A - ë轴承酯基团在3,3'位置上设置具有优异的对映选择性高达99%的高烯丙基醇的良好的产率为广泛的底物范围,其覆盖脂族,芳香族,杂芳香族,和α,β -不饱和醛。阐明了溶剂对转化率和对映选择性的影响,并确定了CH 2 Cl 2被证明是反应的最佳溶剂。另外,还探索了与巴豆基三氯硅烷的烯丙基化反应,结果表明,(E)-巴豆基三氯硅烷具有较好的非对映选择性,有利于其抗异构体的形成。