1,4-Dioxane-Tuned Catalyst-Free Methylation of Amines by CO2 and NaBH4.

A catalyst-free reductive functionalization of CO2 with amines and NaBH4 was developed. The N-methylation of amines was carried out with CO2 as a C1 building block and 1,4-dioxane as the solvent. Notably, the six-electron reduction of CO2 to form the methyl group occurred simultaneously with formation of the C-N bond to give the N-methylated amine.