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.
Phosphine-catalyzed [3+3] annulation reaction of modified tert-butyl allylic carbonates and substituted alkylidenemalononitriles
作者:Suqing Zheng、Xiyan Lu
DOI:10.1016/j.tetlet.2009.05.085
日期:2009.8
A phosphine-catalyzed [3+3] annulation reaction of modified tert-butyl allylic carbonates with various alkylidenemalononitriles to form cyclohexenes was developed. The use of protic solvent is crucial in this reaction. When non-polar solvent, toluene or xylene, was used, only non-cyclized product was obtained. (C) 2009 Elsevier Ltd. All rights reserved.