Asymmetric Synthesis of Tetrahydroquinolines with Quaternary Stereocenters through the Povarov Reaction
作者:Mingsheng Xie、Xiaohua Liu、Yin Zhu、Xiaohu Zhao、Yong Xia、Lili Lin、Xiaoming Feng
DOI:10.1002/chem.201102333
日期:2011.12.2
The asymmetric Povarov reaction with α‐alkyl styrenes as dienophiles was catalyzed by an N,N′‐dioxide L4–Sc(OTf)3 complex. Enantiopure tetrahydroquinoline derivatives with a quaternary stereocenter at the C4 position were synthesized for the first time. A wide variety of α‐alkyl styrenes and N‐aryl aldimines were tolerated in the reaction, to give excellent diastereo‐ (up to 99:1 d.r.) and enantioselectivities
N,N'-二氧化物L4 -Sc(OTf)3配合物催化与α-烷基苯乙烯作为亲二烯体的不对称Povarov反应。首次合成了在C4位置具有四级立体中心的对映体四氢喹啉衍生物。反应中可以耐受多种α-烷基苯乙烯和N-芳基醛亚胺,可提供出色的非对映异构体(高达99:1 dr)和对映选择性(92到> 99% ee))。另外,反应可以以克为单位进行,而没有收率,非对映选择性或对映选择性的任何损失。一个分子间的氢转移反应被发现是一种副反应,它提供了一种方法来合成具有手性季立体中心的相应喹啉衍生物。