RSS-Feed abonnieren
DOI: 10.1055/s-0029-1218230
Synthesis of Arylthiobenzothiazoles via a Copper(I)-Catalyzed S-Arylation
S. Murru, H. Ghosh, S. K. Sahoo, B. K. Patel*
Indian Institution of Technology Guwahati, India
Publikationsverlauf
Publikationsdatum:
20. November 2009 (online)
Significance
Reported are the first one-pot, intra- and intermolecular S-arylations via copper(I) catalysis leading to the direct synthesis of arylthiobenzothiazoles. In this single catalytic one-pot double arylation strategy, intramolecular S-arylation of dithiocarbamate salt 1 afforded benzothiazol-2-thiol (MBT) as intermediate 3 (confirmed by isolation), which undergoes an intermolecular C-S coupling giving 2-arylthiobenzothiazoles 4 directly. After screening of ligands, L1 was found to be optimal in terms of yield and short reaction time under an air atmosphere (no disulfide formation). This catalytic system for double S-alkylation is effective for aryl iodides bearing EWG and EDG substituents. However, the presence of EWGs accelerates the rate of reaction (intermolecular) giving products in shorter times, whereas EDGs retard the reaction. Moreover, bromo- and chloro-arenes were not effective as intermolecular coupling partners.
Review: T. Kondo, T.-a. Mitsudo Chem. Rev. 2000, 100, 3205-3220.