Pd(II)/N,N′-Disulfonyl Bisimidazoline-Catalyzed Enantioselective Synthesis of Cyclic Quaternary Centers and Mechanistic Investigations

A Pd(II)/ N, N ′-disulfonyl bisimidazoline-catalyzed asymmetric 1,4-conjugate addition reaction of low-cost arylboronic acids with readily available β - substituted cyclic enones is described, providing a straightforward way of constructing cyclic all-carbon quaternary stereocenters with high enantioselectivity, in which ≥96% ee was obtained in most cases. The reaction proceeded without the protection of inert gas, making the operation process simple. Theoretical calculations have been applied to understand the origins of enantioselectivity.