Kinetics and mechanisms of homogeneous catalytic reactions. Part 8. Regioselective reduction of benzo[b]thiophene catalyzed by OsH(CO)(κ3-OCOCH3)(PPh3)2

Abstract

The complex OsH(CO)(κ3-OCOCH3)(PPh3)2 (1) catalyzes the reduction of benzo[b]thiophene (BT) to 2,3-dihydrobenzo[b]thiophene (DHBT), under mild reaction conditions. A kinetic study lead to the rate law: r = K 1 K 2 k 3 /{1 + K 1 (1+K 2 )[BT]}[Os][BT][H2]. A catalytic cycle was proposed, which involves the oxidative addition of hydrogen as rate-determining step.