One-pot synthesis and property study on thieno[3,2-b]furan compounds.

Based on the regioselective intermolecular Suzuki coupling and subsequent intramolecular Ullmann C-O coupling reactions, one-pot synthesis of benzo[4,5]thieno[3,2-b]benzofurans (BTBFs) was developed after optimization of the reaction conditions including catalysts, solvents, bases, ligands and reaction times. The one-pot reaction, with only 2 mol% Pd(PPh3)4 and 2 mol% copper(i) thiophene-2-carboxylate (CuTc) as the catalysts, K3PO4·3H2O as the base and tert-butanol as the solvent, afforded moderate to good yields (up to 70%) for a variety of substrates.