Cycloadditions of aromatic azomethine imines with 1,1-cyclopropane diesters

The cycloaddition of aromatic azomethine imines to 1,1-cyclopropane diesters was achieved using Ni(ClO4)(2) as catalyst. The methodology gives access to unique tricyclic dihydroquinoline derivatives with dr up to 6.6:1. A nonconcerted mechanism is proposed on the basis of stereochemical analysis of the reaction.