157304-00-2Relevant academic research and scientific papers
Thermal reaction of imidazolium N-vinylimino ylides: Formation of mesomeric betaines, imidazopyridaziniumides, via back-donated 1,6-cyclization
Matsuda,Yamashita,Takahashi,Ide,Itou,Motokawa,Chiyomaru
, p. 454 - 458 (1994)
The reaction of N-aminoimidazolium salts (4,5) with polarized olefins (2a- d, 3a, b) in the presence of K2CO3 in EtOH gave the corresponding imidazolium N-vinylimino ylides (6, 7). Thermolyses of the N-vinylimino ylides (6c-f. 7a-c) afforded mesomeric betaines (8a-d, 9a,b, 10a,b). Treatment of the salt (5) with polarized olefins (2b-d. 3c) in the presence of K2CO3 in EtOH directly yielded mesomeric betaines (9c-d, 10c), while in EtOH, the reaction of the salt (5) with polarized olefins (2e, 3d) in the presence of K2CO3 gave pyrazoles (11a, b). The formation of mesomeric betaines is suggested to proceed via back-donated 1,6-cyclization.
