Periselectivity in the Lanthanoid-catalyzed Intramolecular Cycloaddition Reactions of 1,7-Dienes: Effects of Ligands and Steric Factors in the Substrates

摘要

Development of effective cyclization reactions for the synthesis of carbocycles and heterocycles has been the subject of extensive study due to their application to medicines and other functional groups. A transition metal-catalyzed intramolecular cycloaddition reaction of unsaturated compounds bearing dienes or enynes has attracted a lot of attention. Previously, we have reported that the Lewis acid-catalyzed reactions of 1,7-dienes possessing chiral sulfinyl groups at the terminal olefinic parts gave intramolecular ene and / or hetero Diels-Alder reaction products with high enantio- (98%) and excellent stereoselectivity in bom cases using EtAlCl2 or Et2AlCl at -78°C.