Reactions between trimethoxymethylsilane and Cab-O-Sil in toluene were conducted in the presence of ethylamine, diethylamine, triethylamine, ammonia, and pyridine. Amines with exchangeable protons were found to catalyze the reaction to a significantly larger extent than those without such protons. However, even pyridine had a catalytic effect. Two mechanisms are proposed to explain the results.