An expedient route to heterocycles througha-arylation of ketones and arylamides bymicrowave induced thermal SRN1 reactions

Abstract

Microwave irradiation promotes a quick aromatic nucleophilic substitution by a thermally induced electrontransfer process to form new C–C bonds by the coupling of aryl radicals and enolate nucleophiles. Diverse2-aryl-1-phenylethanones can be prepared by the directa-arylation of acetophenone with differenthaloarenes. The ketone enolate anion is generated by deprotonation withtBuOK in DMSO and thereaction is carried out in a closed microwave vessel at 70–100 C for 10 min. This simple procedure alsoallows the synthesis of deoxybenzoin and indole heterocycle derivatives by inter- or intra-molecular ringclosure reactions, with moderate to excellent substitution yields.