Imino Diels-Alder reaction of boronates. Preparation and characterization of new 3,4-dihydroquinoline and 1,2,3,6-tetrahydropyridine derivatives

The preparation of 3,4-dihydroquinolines and 1,2,3,6-tetrahydropyridines by imino Diels-Alder reaction of boronates derived from Schiff bases with 2,3-dimethylbutadiene is reported. The results show that the dienophile or diene behavior of these boronates is influenced by the substituent para to the imine fragment.