Silver-Catalyzed Annulation of Arynes with Nitriles for Synthesis of Structurally Diverse Quinazolines.

An efficient silver catalyzed annulation reaction of aryne with nitriles to generate quinazolines is described. Arynes generated from triynes or tetraynes through a hexadehydro Diels-Alder reaction readily participated in an [A + 2B] mode of annulation with nitriles in the presence of AgSbF6 catalyst. The mechanism was explored by DFT calculations, which supports the silver-catalyzed formation of nitrilium ion as a key intermediate. This annulation generates an array of polysubstituted novel quinazoline derivatives with excellent regioselectivity.