Desymmetrizing reductive aldol cyclizations of enethioate derivatives of 1,3-diones catalyzed by a chiral copper hydride
作者:Jun Ou、Wing-Tak Wong、Pauline Chiu
DOI:10.1039/c2ob25206f
日期:——
A range of enethioate derivatives of 1,3-diones underwent reductive aldol cyclizations catalyzed by a chiral copper hydride generated in situ from 5 mol% TaniaPhos (SL-T001-1), 5 mol% Cu(OAc)2·H2O, 5 mol% bipyridine and 2.0 equiv. of PhSiH3, to furnish polycyclic β-hydroxythioester products bearing three newly established contiguous stereocenters, with >98 : 2 dr and in up to 94% yield and 98% ee.
1,3-二酮的一系列烯硫醚衍生物经历了还原性羟醛环化反应,该环化反应由5 mol%的TaniaPhos(SL-T001-1),5 mol%的Cu(OAc)2 ·H 2 O原位生成的手性氢化铜催化5摩尔%联吡啶和2.0等效 PhSiH 3的合成,可提供带有三个新近建立的连续立体中心的多环β-羟基硫酯产品,其dr> 98:2,产率高达94%,ee高达98%。胺的使用,例如联吡啶 或者 2,6-二甲基吡啶作为添加剂导致总反应速率增加。主要的双环醇醛缩合产物具有所有的顺式取代基,并且可以通过经由环状过渡态与二酮还原生成的(Z)-烯酸酯反应而合理化。