Methoxycarbonylation of amines under transition-metal and solvent-free condition with dimethyl carbonate

In this work, KOtBu promoted methoxycarbonylation reaction of amine using dimethyl carbonate (DMC) as carbonyl resource was presented under solvent-free condition. This reaction features mild reaction condition (25-30℃), short reaction time (0.5-3.0 h), broad substrate scope and easy scale-up. Under standard reaction condition, both N-aryl and N-alkyl substituted methyl carbamates (totally 37 examples) could be delivered in moderate to good yield (62-99%). Additonal radical-trapping experiment using TEMPO as radical scavenger was conducted. Furthermore, representative carbamates were prepared in 10.0 g scale with no significant decrease of the yield.