Photodehydrocyclisation of 1-styrylimidazoles; an HMO study
Abstract
Photodehydrocyclisation of 4,5-diphenyl-1-styrylimidazole yields phenanthro[9′,10′:4,5]imidazo[2,1-a]isoquinoline via 1-styrylphenanthro[9,10-d]imidazole. Another possible intermediate, 2,3-diphenylimidazo[2,1-a]isoquinoline, undergoes photo-oxidation to yield 2-benzoyl-1-benzoylimino-1,2-dihydroisoquinoline. HMO calculations, in particular the resulting localisation energies, are a useful guide for predicting the mode of photocyclisation of 1-styrylimidazoles.