Sn(Ot-Bu)(4) is a user-friendly precatalyst for the direct synthesis of dimethyl carbonate from CO2 and MeOH. It is far more active than the conventional Bu2Sn(OMe)(2) catalysts. The addition of acid and/or base cocatalysts as well as optimization of the CO2 pressure improved the catalytic activity. The reaction is proposed to proceed through the formation of a dimeric intermediate composed of six-coordinated tin carbonate complexes.