Oxidative Cyclization of Diamides by Phenyliodoso Acetate

Abstract

Carboxamides containing a suitably situated nucleophilic group ( carboxamide , N-substituted carboxamide, or hydroxymethyl ) undergo oxidation by phenyliodoso acetate to afford heterocyclic products through internal attack on the initially formed isocyanate. N- Substituted carboxamido groups are the least effective of these internal traps. Phenyliodoso acetate is much superior to lead(IV) acetate for oxidative cyclization of maleamide and various substituted propanediamides, but is not suitable for butanediamide.