An improvement in the process for the preparation of N-allyl-O-alkyl thionocarbamates by the reaction of an allyl isothiocyanate with an alcohol is disclosed which comprises the use of a catalyst of the general formula: ##STR1## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, and R.sub.5 are individually selected from alkyl or aryl or a mixture thereof, M represents a metal from Group III B, IV B, or V B of the Periodic Table of the Elements, and n is the integer 0 or 1; provided that the sum of n.sub.1, n.sub.2, n.sub.3, n.sub.4, and n.sub.5 equals the valance of said metal M.