Jun-ichi Kawakami

Platinum-catalyzed highly selective thiocarbonylation of acetylenes with thiols and carbon monoxide

Abstract A novel carbonylative addition of thiols (RSH) to terminal acetylenes (R′–CCH) takes place successfully in the presence of platinum catalysts under the pressure of carbon monoxide, providing α,β-unsaturated thioesters (R′–C(C(O)SR)CH 2 ) in good yields regioselectively. This ‘hydrothiocarbonylation’ reaction of acetylenes may include the formation of the platinum sulfide complex as key species.

Rhodium-catalyzed highly selective thioformylation of acetylenes with thiols and carbon monoxide

Abstract Highly regioselective thioformylation of terminal acetylenes with thiols and carbon monoxide has been developed by the use of rhodium(I) complexes as the catalyst: formyl and thio groups are introduced into the terminal and inner positions of acetylenes, respectively. The thioformylation is performed in the presence of a catalytic amount of rhodium(I) complexes, such as RhH(CO)(PPh 3 ) 3 , RhCl(PPh 3 ) 3 , and RhCl(CO)(PPh 3 ) 2 , under the pressure of CO (3 MPa) at 120°C in CH 3 CN to provide β-thio-α,β-unsaturated aldehydes in good yields. This thioformylation can be applied to a variety of terminal acetylenes and aromatic thiols. A mechanistic proposal includes the formation of the rhodium sulfide complex as the key species.