How 2-anilinovinyl perfluoroalkyl ketones can be mechanistically correlated with their cyclization products 2-(perfluoroalkyl)quinolines

When heated in the presence of phosphoryl chloride, 2-anilinovinyl perfluoroalkyl ketones [e.g., 4-anilino-1,1,1-trifluoro-3-buten-2-one] gave 2-(perfluoroalkyl)quinolines [e.g., 2-(trifluoromethyl)quinoline]. As revealed by cross-over expts., an efficient amine exchange process randomizes the structural component in the final products but not in their aminoenone precursors. 1,3-Diaminoallyl cations (vinylogous formidinium salts) are postulated to act as the turntables. [on SciFinder (R)]