The invention comprises a curable composition comprising: (i) a blocked reactive component wherein the blocked reactive component is a blocked isocyanate or a blocked isothiocyanate; (ii) a functional compound reactive with the blocked reactive component, the functional compound containing reactive hydrogen; (iii) a catalyst for promoting the reaction of the reactive component with the blocked functional compound, wherein said catalyst is based on the reaction product of manganese, cobalt, nickel, copper, zinc, germanium, antimony, or bismuth, or the oxides thereof with a mercaptan, or an organic acid, wherein said organic acid is hexanoic, oxalic, adipic, lactic, tartaric, salicylic, thioglycolic, succinic, or mercapto succinic acid, or the reaction product of copper or germanium, or the oxides thereof with a lower aliphatic acid. The manganese, cobalt, nickel, copper, zinc, germanium, antimony, or bismuth catalysts can be used in conjunction with other compounds to promote the reaction, especially compounds based on tin, preferably organotin compounds. Water soluble catalysts are preferred. The coating composition can be electrocoated on a conductive substrate and cured.