Divergent synthesis of carbamates and N-methyl carbamates from dimethyl carbonate and nitroarenes with Mo(CO)6 as a multiple promoter.

Abstract

Dialkyl carbonates are green and versatile reagents that can be used in alkylation and alkoxycarbonylation reactions. Herein, we disclosed a reductive methoxycarbonylation of aromatic nitro compounds with dimethyl carbonate for the construction of diverse carbamates and N-methyl carbamates. Using Mo(CO)6 as a multiple promoter, different nitroarenes were smoothly transformed into the corresponding carbamates in yields between 27 and 94% using DMC as both solvent and reagent. It is worth noting that the choice of different bases allowed the desired products to be controlled: K3PO4 favoured the formation of carbamates as the primary product, whereas DBU facilitated the formation of N-methyl carbamates as the main product.