Synthesis of benzyl substituted tetrahydropyridines and 1,2,3,4- tetrahydroisoquinolines via acid catalyzed cyclization of γ,δ-unsaturated N-formyl-N-styryl amines

Article abstract of DOI:10.1016/S0040-4020(99)00136-2

Acid-catalyzed cyclization of N-(3-methylbut-3-enyl)-N-styrylformamides 1-3 in the presence of 9-BBN triflate gave access to 2-benzyl-1-formyl-4- methyl-1,2,5,6-tetrahydropyridines 4a-6a and minor amounts of the isomeric 1,2,3,6-tetrahydropyridines 4b-6b.