Divergent [5 + 1] Annulation of <i>o</i>-Aminobenzamides with Vinylene Carbonate as a Multifunctional Reagent

A divergent [5 + 1] cyclization reaction of <i>o</i>-aminobenzamides with vinylene carbonate has been developed, rapidly generating three types of cyclic molecules including quinazolinones, 2-methylquinazolinones, and 2,3-dihydroquinazolinones with high chemoselectivity. In this discovery, vinylene carbonate blooms as a multifunctional reagent to participate in cyclization. The potential of this new finding is further emphasized by assembling the benzothiazole heteroarene via the [4 + 1] version and tolerating bioactive units well.