A Chiral Cagelike Copper(I) Catalyst for the Highly Enantioselective Synthesis of 1,1‐Cyclopropane Diesters

Triangulation method: The catalytic enantioselective cyclopropanation of multisubstituted olefins with phenyliodonium ylide malonate has been achieved in the presence of a chiral bisoxazoline copper(I) complex (see scheme). A wide range of substrates undergo the reaction to provide optically active 1,1-cyclopropane diesters in high yield with up to >99 % ee. A rationale for the enantioselective induction has been proposed.