A series of 2-aminobenzothiazoles were synthesized by a palladium-catalysed oxidative coupling with good yields (62–89%). Iodobenzene was found to be effective as an additive in this intramolecular C–S bond-formation reaction. The directing thiourea group attached to the aryl ring is essential for the activation of the ortho C–H bond.
A Pd-catalysed regioselective synthesis of 4,5-disubstituted 7-membered N/O-heterocycles was achieved via the 7-endo-dig cyclization followed by C–C bond formation of 2-(1-alkynyl)phenylacetamide.
The regioselective synthesis of benzo[4,5]imidazo[2,1-b]thiazole derivatives via amination (C–N) and intramolecular cyclization (C–S) reactions in the presence of molecular iodine has been reported. This method is base and metal free and features inexpensive catalysts, with a simple procedure and a short reaction time.
Iodobenzene-Promoted Pd-Catalysed ortho-Directed C–H Activation: The Synthesis of Benzothiazoles via Intramolecular Coupling
