Enantioselective Copper-Catalyzed Conjugate Addition of Dimethylzinc to 5-(1-Arylalkylidene) Meldrum’s Acids
作者:Eric Fillion、Ashraf Wilsily、Tiantong Lou
DOI:10.1055/s-0029-1216845
日期:2009.6
The asymmetric formation of all-carbon quaternary benzylic stereocenters containing a methyl substituent was realized by the enantioselective copper-catalyzed 1,4-addition of dimethylzinc to alkylidene Meldrum’s acids in the presence of a chiral phosphoramidite. Copper source and ligand optimization studies are presented, as well as the scope and limitations of dimethylzinc addition to various alkylidene
在手性亚磷酰胺的存在下,通过对映选择性铜催化的二甲基锌与亚烷基梅德鲁姆酸的对映选择性铜催化,实现了含甲基取代基的全碳季苄基立体中心的不对称形成。提出了铜源和配体优化研究,以及二甲基锌添加到各种亚烷基Meldrum酸中的范围和局限性。获得了良好至优异的产率和对映选择性。 梅德鲁姆酸-全碳四元立体中心-对映选择性共轭加成-铜催化-有机锌试剂-亚磷酰胺配体