화학공학소재연구정보센터
Journal of the American Chemical Society, Vol.137, No.11, 3803-3806, 2015
Use of a New Spirophosphine To Achieve Catalytic Enantioselective [4+1] Annulations of Amines with Allenes To Generate Dihydropyrroles
Due in part to the common occurrence of five-membered nitrogen heterocycles in bioactive molecules, the discovery of methods for the enantioselective synthesis of such structures is a useful endeavor. Building on a single example by Tong, of a phosphine-catalyzed [4 + 1] annulation of an amine with an allene that furnished an achiral dihydropyrrole in 22% yield, we have developed, with the aid of a new chiral spirophosphine catalyst, a method with increased utility, specifically, improved yield, enhanced scope (the use of gamma-substituted allenes), and good ee. The enantioenriched dihydropyrrole products can be transformed into other interesting families of compounds with very good stereoselectivity.