Fig. 3 Examples of quinazolines prepared by tandem aza-Wittig/electrocyclization, heterocyclization, three-component reaction

Rossi et al. have utilized the tandem aza-Wittig/electrocyclization principle for synthesis of quinazoline ring (35) and (36) starting from N-imidoyl iminophosphorane (34) [136,137] (Scheme 2). Other unique synthetic strategies with N-vinyliminophosphoranes by Nitta [138], Palacios [139], and benzotriazolyl derivatives by Katrizky [140] have also been developed demonstrating the maturity and excellent prospects of iminophosphorane-mediated syntheses.

NYPh RCHO, xylene, reflux

NYPh RCHO, xylene, reflux

PPh3 6jc electrocyclization

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