Solution and Solid-State Studies of a Chiral Zinc–Sulfonamide Complex Relevant to Enantioselective Cyclopropanations

A highly distorted tetrahedron formed by the four nitrogen atoms around zinc in the crystalline zinc–sulfonamide complex 1 may explain its catalytic activity in asymmetric cyclopropanations. The agent is formed by deprotonation of (R,R)-N,N′-cyclohexane-1,2-diyl)bis(n-butanesulfonamide) with diethylzinc and addition of 2,2′-bipyridyl.