An Organocatalytic Cascade Approach toward Polysubstituted Quinolines and Chiral 1,4-Dihydroquinolines-Unanticipated Effect of N-Protecting Groups
作者:Xinshuai Zhang、Xixi Song、Hao Li、Shilei Zhang、Xiaobei Chen、Xinhong Yu、Wei Wang
DOI:10.1002/anie.201202161
日期:2012.7.16
of a divergent organocatalytic aza‐Michael/aldol cascade process toward quinolines and 1,4‐dihydroquinolines depends on the choice of the N‐protecting group (see scheme; TEA=triethylamine, TMS=trimethylsilyl). Use of an electron‐donating sulfonyl group results in an unanticipated aza‐Michael/aldol/aromatization cascade to give polysubstituted quinolines (right). In contrast, chiral 1,4‐dihydroquinolines
保护问题:有机合成的有机催化氮杂Michael / aldol级联反应向喹啉和1,4-二氢喹啉的反应取决于N保护基的选择(参见方案; TEA =三乙胺,TMS =三甲基甲硅烷基)。给电子的磺酰基的使用会导致意料之外的氮杂-迈克尔/羟醛/芳香化反应级联反应,生成多取代的喹啉(右图)。相反,手性的1,4-二氢喹啉具有吸电子磺酰基(左)。