Bicyclic (alkyl)(amino)carbene (BICAAC) in a dual role: activation of primary amides and CO2 towards catalytic N-methylation

Abstract

Herein, we report the first catalytic methylation of primary amides using CO₂ as a C1 source. A bicyclic (alkyl)(amino)carbene (BICAAC) exhibits dual role by activating both primary amide and CO₂ to carry out this catalytic transformation which enables the formation of a new C–N bond in the presence of pinacolborane. This protocol was applicable to a wide range of substrate scopes, including aromatic, heteroaromatic, and aliphatic amides. We successfully used this procedure in the diversification of drug and bioactive molecules. Moreover, this method was explored for isotope labelling using ¹³CO₂ for a few biologically important molecules. A detailed study of the mechanism was carried out with the help of spectroscopic studies and DFT calculations.