Arylative Methylation of 2,3-Dihydropyrazines and Pyrazinones Using Dimethyl Sulfoxide as a C1 Source

Manganese-catalyzed Efficient Synthesis of N-heterocycles and Aminoketones Using Glycerol as a C3 Synthon

Glycerol is one of the important biomass-derived feedstocks and the high-value utilizations of glycerol have attracted much attentions in recent years. Herein, we report a manganese catalyzed dehydrogenative coupling of glycerol with amines for the synthesis of substituted 2-methylquinoxalines, 2-ethylbenzimidazoles, and α-aminoketones without any external oxidant. In these reactions, NHC-based pincer manganese complex featuring a pyridine backbone displayed high catalytic activity and selectivity, in which hydrogen and water were produced as the only by-products using glycerol as a C3 synthon.

DMSO-DCE Triggered Chemodivergent C-Methylenation of Electron-Rich Arenes: An Easy Access to Diarylmethanes

The chemodivergent property of dimethyl sulfoxide (DMSO) along with 1,2-dichloroethane (DCE) was exploited for the incorporation of a methylene group to form diarylmethanes through a dearomatization/rearomatization process. Methyl(methylene)sulfonium ions (CH2=S+-Me) were generated by simple heating of commonly used solvents such as DMSO and DCE. These ions were subsequently trapped by electron-rich arenes and heteroarenes, resulting in the synthesis of both symmetrical and unsymmetrical diarylmethanes. This protocol was further extended to access N-methylenamides by reacting 2-naphthol with amides or nitriles in the presence of DMSO and DCE.