Enantioenriched tetrasubstituted thiochromanes have been synthesized using a tandem Michael addition-Knoevenagel reaction between 2-mercaptobenzaldehydes and benzylidenemalonates with a 9-epi-aminoquinine thiourea derivative as the catalyst. Steric and electron effects were found to affect profoundly the enantioselectivity and diastereoselectivity of the reaction.
使用 2-巯基
苯甲醛和
亚苄基丙二酸酯之间的
串联迈克尔加成-Knoevenagel 反应,以 9-表
氨基
奎宁硫脲衍
生物为
催化剂,合成了对映体富集的四取代
硫色满。发现空间和电子效应深刻地影响反应的对映选择性和非对映选择性。