摘要 : A catalytic asymmetric [4+2] cyclization of para-quinone methide (p-QM) derivatives with 3-alkyl-2-vinylindoles in the presence of a chiral phosphoric acid has been established, and this method provides chiral chroman frameworks i... 展开 A catalytic asymmetric [4+2] cyclization of para-quinone methide (p-QM) derivatives with 3-alkyl-2-vinylindoles in the presence of a chiral phosphoric acid has been established, and this method provides chiral chroman frameworks in good yields (up to 98%) with high diastereoselectivities (up to >95:5 dr) and excellent enantioselectivities (up to 96% ee). This reaction represents the first catalytic asymmetric [4+2] cyclization of p-QM derivatives with electron-rich alkenes, which will enrich the field of catalytic asymmetric reactions of p-QM derivatives. In addition, this catalytic asymmetric cyclization was successfully applied to 3-alkyl-2-vinylindoles. More importantly, this reaction will offer a useful method for the construction of enantioenriched chroman frameworks. 收起