Ultrasonication Assisted α‐Arylation of N‐heteroarenes Employing 1‐Aryltriazenes Promoted by Brønsted Acidic Ionic Liquid under Aerobic Conditions

Abstract

An efficient and facile methodology for the synthesis of α‐arylated N‐heteroarenes was developed under aerobic conditions by means of ultrasound assistance, as well as conventional heating via a direct α‐arylation protocol employing Imidazolium based ionic liquids serving as both acid promoter and solvent. Structurally diverse N‐heteroarenes and 1‐aryltriazenes were evaluated for this reaction. This methodology has successfully provided a synthetic handle for various electron‐rich and electron‐deficient arylated N‐heteroarenes under metal and/or peroxide free conditions in good to excellent yields. The total synthesis of the known oxoisoaporphine class of alkaloids Menisporphine & Daurioxoisoporphine C was successfully accomplished using the current methodology as a key step in the total synthesis.