Highly Enantioselective Regiodivergent Allylic Alkylations of MBH Carbonates with Phthalides
作者:Fangrui Zhong、Jie Luo、Guo-Ying Chen、Xiaowei Dou、Yixin Lu
DOI:10.1021/ja303115m
日期:2012.6.20
Phthalides were used for the first time in the allylic alkylation reactions with MBH carbonates for the creation of chiral 3,3-disubstituted phthalides. Highly enantioselective regiodivergent synthesis of gamma-selective or beta-selective allylic alkylation products was achieved by employing bifunctional chiral phosphines or multifunctional tertiary amine-thioureas as the catalyst, respectively. It was demonstrated that proper selection of catalysts and reaction conditions would differentiate an S(N)2'-S(N)2' pathway and an addition-elimination process, yielding different regioisomers of the allylic alkylation products in a highly enantiomerically pure form.