A Highly Stereoselective Metal-Free Hydrogenation of Diimines for the Synthesis of Cis-Vicinal Diamines

A highly stereoselective metal-free hydrogenation of vicinal diimines has been successfully realized for the first time using 5-10 mol % of Piers borane as a catalyst under mild conditions, and a variety of cis-1,2-diamines were obtained in 92-99% yields. The current work provides a novel and efficient approach for the synthesis of vicinal diamines.