Xu Y1, Huang D1, Wang KH1, Ma J1, Su Y1, Fu Y1, Hu Y1,2.
J Org Chem. 2015 Dec 18;80(24):12224-33. doi: 10.1021/acs.joc.5b02154. Epub 2015 Nov 30.A concise and efficient method for the synthesis of α-methylene-γ-lactams is developed from multicomponent one-pot reactions of aldehydes or ketones, hydrazides, and ethyl 2-(bromomethyl)acrylate promoted by tin powder. The reaction proceeds smoothly under mild reaction conditions without using any catalyst to give the corresponding products in high yields. α-Methylene-γ-spirolactams can also be prepared from cyclic ketones.