Abstract
The pyrrolidine enamine 1 of deoxybenzoin reacted with diphenyl phosphorazidate (DPPA, (C6H5O)2P (O) N3) to give two amidines, the 1, 2-migration product 7a and the 1, 3-dipolar elimination product 8a in a ratio of 77 : 23. The reaction of DPPA with the enamine 2 of benzyl 2-pyridyl ketone proceeded slightly better in the presence of boron trifluoride etherate, giving both the 1, 2-migration and 1, 3-dipolar elimination products 7b and 8b. However, the main products in the reaction of DPPA with the pyrrolidine enamine 3 of 2-phenacylpyridine were 4-phenyl-5-(2-pyridyl)-1, 2, 3-triazole (11) and diphenyl N-pyrrolidinophosphoramidate (12e). Some other 1, 3-dipolar cycloadditions of enamines with organic azides were also investigated.
