This review recaps the achievements in the field of metal-catalyzed asymmetric direct hydrogenation of nonactivated and activated imines. A summary of the reported catalytic systems with the corresponding reactivity, selectivity, and limitations are given including a discussion about the effects of some reaction conditions on the enantioselectivity of imine hydrogenation. An analysis of proposed imine hydrogenation mechanisms is discussed.

Biaryls have widespread applications in organic synthesis. However, sequentially polysubstituted biaryls are underdeveloped due to their challenging preparation. Herein, we report the synthesis of dissymetric 2,3,2′,3′,4-substituted biaryls via pericyclic reactions of cyclic diaryl λ3-bromanes. The functional groups tolerance and atom economy allow access to molecular complexity in a single reaction step. Continuous flow protocol has been designed for the scale-up of the reaction, while postfunctionalizations have been developed taking advantage of the residual Br-atom.