Metal Carbene-Directed Intramolecular Vinylogous Reactions of Vinyldiazoacetates

Intramolecular addition reactions of electrophilic metallovinylcarbenes with nucleophiles that do not have access to the carbene center undergo addition to the vinylogous position, forming products that rely on subsequent transformations of vinylmetal intermediates. Catalytic addition to a carbon-carbon double bond elicits the formation of an intermediate carbocation whose proton loss causes protodemetalation of the vinylmetal intermediate. Addition to the azido group results in the formation of aliphatic 1,2,3-triazines by [3 + 3]-cycloaddition. Catalytic intramolecular reactions with a carbamate nucleophile yield a carbonyl ylide whose loss of isobutylene produces oximidovinyl-oxazolidinone esters with high enantioselectivity. Comparisons are made between rhodium, copper, gold, and silver catalysts