Lewis acid-mediated cycloaddition of methylenecyclopropanes with aldehydes and imines: A facile access to indene, THF, and pyrrolidine skeletons via homoallylic rearrangement protocol
Methylenecyclopropanes (MCPs) 1 can react with aldehydes and aldimines to give the corresponding indene, THF, and pyrrolidine cycloaddition products in the presence of (BF3OEt2)-O-. under mild reaction conditions.
Shi M,Xu B,Huang JW. Lewis acid-mediated cycloaddition of methylenecyclopropanes with aldehydes and imines: A facile access to indene, THF, and pyrrolidine skeletons via homoallylic rearrangement protocol[J]. Org. Lett.,2004,6(7):1175-1178.