Nickel-Catalyzed Asymmetric Hydrogenation of Cyclic Alkenyl Sulfones, Benzo[b]thiophene 1,1-Dioxides, with Mechanistic Studies

A highly efficient catalytic system based on the cheap transition metal nickel for the asymmetric hydrogenation of challenging cyclic alkenyl sulfones, 3-substituted benzo[b]-thiophene 1,1-dioxides, was first successfully developed. A series of hydrogenation products, chiral 2,3-dihydrobenzo[b]-thiophene 1,1-dioxides, were obtained in high yields (95-99%) with excellent enantioselectivities (90-99% ee). According to the results of nonlinear effect studies, deuterium-labeling experiments, and DFT calculation investigations, a reasonable catalytic mechanism for this nickel-catalyzed asymmetric hydrogenation was provided, which displayed that the two added hydrogen atoms of the hydrogenation products could be from H-2 through the insertion of Ni-H and subsequent hydrogenolysis.

Automated summary

A highly efficient catalytic system based on inexpensive transition metal nickel was developed for the asymmetric hydrogenation of challenging cyclic alkenyl sulfones. The study provided a reasonable catalytic mechanism for the nickel-catalyzed asymmetric hydrogenation, showing that the hydrogenation products could originate from H-2 through the insertion of Ni-H and subsequent hydrogenolysis.