Copper-catalyzed intramolecular iminolactonization cyclization reactions of remote C(sp3)–H bonds in carboxamides†
Abstract
Iminolactones are an important class of heterocyclic compounds. Thus, the development of an efficient strategy for their preparation becomes highly desirable. A new method for the transformation of carboxamides into iminolactones via copper-catalyzed intramolecular C(sp3)–H bond functionalization is reported herein. A series of primary, secondary and tertiary C(sp3)–H bonds were all accommodated to afford iminolactones through a cascade process which involves amidyl radical intermediate generation, 1,5-HAT (hydrogen atom transfer), and ensuing cyclization.