Nitrogen-containing organobases as promoters in the cobalt(II)–Schiff base catalyzed oxidative carbonylation of amines

The use of organic bases as promoters in the cobalt(II)–Schiff base complex catalyzed oxidative carbonylation of amines was investigated. The generality of the reaction was also studied by submitting different amines to the same procedure and by changing the reaction conditions. Very good yields in the corresponding ureas were achieved in toluene with a catalyst loading of 0.5 mol % and using TBD (1,5,7-triazabicyclo[4.4.0]dec-5-ene) as promoter. Methyl carbamates were obtained in methanol.