An expedient route to heterocycles through α-arylation of ketones and arylamides by microwave induced thermal SRN1 reactions

Abstract

Quick reaction by microwave irradiation promotes nucleophilic substitution by thermally induced electron transfer mechanism and allows to synthesize deoxibenzoin and indol heterocycles derivates by inter or intramolecular ring closure.

Abstract

Microwave irradiation promotes a quick aromatic nucleophilic substitution by a thermally induced electron transfer process to form new C–C bonds by the coupling of aryl radicals and enolate nucleophiles. Diverse 2-aryl-1-phenylethanones can be prepared by the direct α-arylation of acetophenone with different haloarenes. The ketone enolate anion is generated by deprotonation with tBuOK in DMSO and the reaction is carried out in a closed microwave vessel at 70–100 °C for 10 min. This simple procedure also allows the synthesis of deoxybenzoin and indole heterocycle derivatives by inter- or intra-molecular ring closure reactions, with moderate to excellent substitution yields.