Till date, remarkable progress has been made in the development of photocatalysts owing to their high activity, selectivity and tunable light absorption in visible light range. Recently, the heterogeneous photocatalytic...

Unsymmetrical one-pot sequential cross-coupling reactions of sterically hindered tetrabromothiophene with arylboronic acid and an alkyne/alkene to afford selective bi-, tri-, and tetrasubstituted aryl/alkynyl-thiophenes with the aid of a palladium catalyst were described. The reaction proceeds via a site-selective Suzuki/Sonogashira coupling, followed by selective Sonogashira, Suzuki and Heck coupling reactions. This methodology has demonstrated an important framework for the synthesis of organic scaffolds.

Herein, we report the 6-exo-dig ring closure of ortho-alkynylanilines with readily available aroyl isothiocyanate.

An environmentally benign, transition-metalfree organic base promoted one-pot cascade synthesis of highly functionalized benzo[d]thiazol-2(3H)-ylidene benzamide in the presence of water was accomplished by threecomponent reaction of ortho-iodoanilines, acrylates, and aroyl isothiocyanates. The protocol involves the in situ generation of thiourea intermediate followed by triethylamine induced intramolecular SN Ar displacement reaction and subsequent Michael addition onto acrylate leads to the formation of benzo[d]thiazol-2(3H)-ylidene benzamide. Benzo[b]thiazole is also generated in good yields using amidation and intramolecular aromatic nucleophilic substitution chemistry. The control experiments support the proposed mechanistic pathway. Further X-ray crystallographic studies confirmed the assigned structures of the fused benzamide.