New synthesis of nitrogen heterocycles through amide-directed hydrocarbonylation of alkenamides catalyzed by rhodium complexes

Amide-directed hydrocarbonylation of 3-butenamide(1) catalyzed by rhodium complexes such as RhCl(PPh 3 ) 3 , RhCl(CO)(PPh 3 ) 2 , HRh(CO)(PPh 3 ) 3 , and Rh 4 (CO) 12 gives a mixture of 3,4-dihydro-2-pyridone (2), 4-methyl-3-pyrrolin-2-one (3), and a unique heterodimer, 6-(4-methyl-2-oxo-3-pyrrolin-1-yl)-2-piperidone (4)