Efficient rhodium catalysts for the hydrogenolysis of thiophenic molecules in homogeneous phase

Abstract

In the presence of strong bases, the CS insertion complexes (triphos)Rh[ η 3-S(C 6H 4)CHCH 2] and (triphos)Rh( η 3-SCHCHCHCH 2) as well as the π-alkyne complex [(triphos)Rh( η 2-MeO 2CCCCO 2Me)]PF 6 are catalyst precursors for the hydrogenation of thiophene (T), benzo[ b]thiophene (BT) and dibenzo[ b, d]thiophene (DBT) in tetrahydrofuran solution [triphos = MeC(CH 2PPh 2) 3]. Both hydrogenolysis (thiols) and desulfurization (hydrocarbons) products are obtained. Among the substrates investigated, BT is the most reactive, whereas T is the easiest to desulfurize.