Toward transition metal-catalyzed carbonylation of methanol without hl as copromoter: Catalytic exocyclic carbonylation of cycloimino esters

Initial studies of a rare exocyclic C-O bond carbonylation are reported. Under the catalysis of Co-2(CO)(8) in the absence of HI as the copromoter, cycloimino esters are carbonylated to afford N-acyllactams in high yields under relatively mild conditions (100-160 degreesC and 200-1000 psi). The reaction is interesting because it opens up the possibility of carbonylation of alcohols in the absence of HI.