1,2-Diamines as the Amine Sources in Amidation and Rhodium-Catalyzed Asymmetric Reductive Amination Cascade Reactions

Sulfur-Promoted Access to 3-Arylquinoxalin-2-ones by Oxidative Coupling of o-Phenylenediamines with Arylacetates

We disclose the synthesis of 3-arylquinoxalin-2-ones from o-phenylenediamines and readily available arylacetates. The method harnesses the selective oxidative property of elemental sulfur in the presence of amine base catalyst and DMSO. The reactions are operationally simple and tolerate a wide range of functional groups.

Facile access to C-substituted piperazin-2-ones and mianserin derivative enabled by chemoselective carbene insertion and cyclization cascade

The chemoselective N-H insertion of unsymmetrical diamines into carbene is a longstanding challenge. A simple copper-catalyzed strategy for synthesizing C-substituted piperazinones is described, employing easily accessible diazo compounds and 1,2-diamines. The reaction proceeded via chemo-selective carbene insertion at the comparatively less nucleophilic amine, followed by instantaneous cyclization. The protocol was further extended to access NH-free piperazinone, and the synthesis of a Mianserin derivative.

Cobalt-Catalyzed Enantioselective Reductive Amination of Ketones with Hydrazides

An efficient cobalt-catalyzed asymmetric reductive amination of ketones with hydrazides has been realized, directly producing valuable chiral hydrazines in high yields and enantioselectivities (up to 98% enantiomeric excess).

Development of spirocyclic phosphoramidite-based hybrid diphosphorus ligands for enantioselective iridium-catalyzed hydrogenation of imines

Novel spirocyclic phosphine–phosphoramidite ligands for highly efficient and enantioselective Ir-catalyzed hydrogenation of various imines.