104488-59-7Relevant academic research and scientific papers
Ring Opening of N-(Tetraalkylamidinio)pyridinium Salts by Anions of CH-Acidic Methylene Compounds
Feith, Bernhard,Weber, Hans-Martin,Maas, Gerhard
, p. 3276 - 3296 (2007/10/02)
N-Carbeniopyridinium salts 2, 4, 14, and 18 offer three sites to nucleophilic attack; depending on the reactants, all three modes have been realized.With anions of CH-acidic methylene compounds, α-attack at the pyridinium ring followed by ring opening leads to azahexamethine merocyanines (8, 15, 23).In some cases, kinetically controlled reactions yield 1,4-dihydropyridines which isomerize thermally to give 1,2-dihydropyridines which undergo ring opening spontaneously.Also, nucleophilic attack at the cationic substituent of the N-carbeniopyridinium salts is possible as is indicated by the formation of push-pull olefins 11, 16 and of enol ether 12.
