Chiral CO<sub>2</sub>-Synthons via Catalytic Asymmetric Hetero-Diels−Alder Reactions of Ketomalonate and Dienes
作者:Sulan Yao、Mark Roberson、Frank Reichel、Rita G. Hazell、Karl Anker Jørgensen
DOI:10.1021/jo990696i
日期:1999.9.1
A catalytic enantioselective approach for the formation of chiral CO(2)-synthons is presented. The described methodology is based on the reaction of dienes with diethyl ketomalonate using C(2)-symmetric bisoxazolines as the chiral ligands and copper(II) and zinc(II) as the Lewis acids. For cyclic dienes the reaction proceeds in good yield and with up to 93% ee for 1,3-cyclohexadiene, while for cyclopentadiene