Base-mediated benzannulation of α-cyanocrotonates with ynones: facile synthesis of benzonitriles and fluorenes

Abstract

Here, we have demonstrated a strategic rapid approach for the synthesis of benzonitriles and cyanofluorenes via the [3 + 3] benzannulation of readily available alkynones and α-cyanocrotonates, a protocol par excellence for aryl nitriles. This decarboxylative annulation has been assisted solely by a base without the need for any catalyst. The only by-product is EtOH (and CO₂) and the product is cleanly filtered from the contents after the reaction at an ambient temperature.