Tin- or titanium-catalyzed dimethyl carbonate synthesis from carbon dioxide and methanol: Large promotion by a small amount of triflate salts

The Bu(2)SnO- or Ti(O-i-Pr)(4)-catalyzed dimethyl carbonate (DMC) synthesis starting from methanol, carbon dioxide, and dimethyl ketal was remarkably accelerated by the addition of a small amount of [Ph(2)NH(2)]OTf (N:Sn = 1:10); conventional acids such as H(2)SO(4), HCl, and H(3)PO(4) were not effective to promote the DMC synthesis. (C) 2008 Elsevier B.V. All rights reserved.