Preparation of Tricyclic Guanidines from C,C-Bis(iminophosphoranes).

Article abstract of DOI:10.1016/0040-4020(95)00196-F

Aza Wittig-type reaction of C,C-bis(iminophosphorane) 4, derived from 2,5-bis(o-aminophenyl)pyrrole, with two equivalents of aryl isocyanates directly provided the tricyclic guanidines 9, which underwent elimination of the corresponding diarylcarbodiimide by thermal treatment to give the parent <5,6,6> tricyclic guanidine 13.