Preparation of Hydantoins by Catalytic Oxidative Carbonylation of α-Amino Amides

Hydantoins can be synthesized from the corresponding amino amides employing oxidative catalytic carbonylation using W(CO)(6) as the catalyst, I(2) as the oxidant, CO as the carbonyl source, and DBU as base. Secondary amides afford the hydantoins in good to excellent yields, which decrease as the steric bulk of the N-alkyl substituent increases.