Abstract Copper-catalyzed decomposition of alkyl diazoacetates in the presence of semicyclic enaminones 1a–o leads primarily to enamino esters 2 which constitute formal products of C–C insertion of the carbene unit. In the case of N-methyl (1a–e) and N-benzyl (1f–i) enaminones, 2a–i are accompanied by 2, 3, 5, 6-tetrahydroindoles 3a–i, in which two carbene moieties are incorporated. At 250 C, compounds 2b–e, which could not be ...
