Ligand-free copper powder-catalyzed and (KOBu)-Bu-t-accelerated expeditious synthesis of substituted benzoxazoles

摘要

A general method for the synthesis of substituted benzoxazoles via copper powder-catalyzed and (KOBu)-Bu-t-accelerated cyclization of ortho-iodoanilides is described. This is facile, efficient, and very rapid synthesis which is believed to proceed via an intramolecular C-O cross-coupling and oxidative insertion/reductive elimination pathway through a Cu(0)/Cu(II) manifold. (C) 2015 Elsevier Ltd. All rights reserved.