Platinum-Catalyzed Reaction of Alkynes with ArI (Ar = aryl and thienyl) and Ar‘SM (M = Na, K, and Sn(Bu-n)3): Three- vs Two-Component Cross-Coupling Reaction

The Pt-catalyzed reactions of terminal alkynes HCCR ( 2 ) with ArI ( 6 ) (Ar = aryl and thienyl) and Ar‘SM (M = Li, Na, K, and Sn( n -Bu 3 )) ( 7 ) have been examined. Among them, the combined use of 2- and 3-iodothiophene with PhSK resulted in the formation of ( Z )-Ar(H)C C(SAr‘)(R) ( 5 ) in moderate to good yields. When aryl iodide was employed as a coupling partner, thioether ArSAr‘ ( 4 ), a direct cross-coupling product between 6 and 7, was competitively produced together with 5 . The ratios of formation of 5 / 4 were significantly dependent on the substituent in Ar of 6 and Ar‘ of 7 as well as species of 2 . The mechanistic study indicated that 4 was produced by the alkyne-participated reaction of 6 with Pt(Ar)(SAr‘)(PPh 3 ) 2 ( 1 ).