Cross-Conjugated and Psaeudo-Cross-Conjugated Mesomeric Betaines. 1. Synthesis and Characterization

Article abstract of DOI:10.1021/jo00248a002

Reaction of pyrazoles, 1,2,3-triazoles, and 1,2,4-triazoles with aryl(chlorocarbonyl)ketenes, alkylmalonyl dichlorides, or carbon suboxide results in a series of cross-conjugated mesomeric betaines, characterized by the presence of distinct cationic and anionic segments. 1-Substituted imidazoles, suitably substituted 1,2,4-triazoles, and pyridine with the above reagents give rise to pseudo-cross-conjugated mesomeric betaines which, in addition to charge separation, are characterized by the presence of the 2-oxyallyl cation 1,3-dipole.Alternative syntheses of cross-conjugated mesomeric betaines which allow the introduction of more diverse substituents are also described.