There have been many studies on various aspects of the cis-trans thermal and photochemical isomerization of azastiibenes and their quaternary salts [1-3], although several questions have not yet been fully elucidated. Thus, the cis-l-methyl-2-(2-phenylethenyi)pyridinium salt was found to form in alkylation of cis-2-styrylpyridine by methyl tosylate [2]. %Rx g ... - IX- R I lla, b Ilia. b II, Ill a R = CH 3, b R = CH,Ph: X = CI. I, OSOzPh ... In the present work, we discovered ...
