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
journal contributionposted on 30.01.2006, 00:00 by Hitoshi Kuniyasu, Fumikazu Yamashita, Takayoshi Hirai, Jia-Hai Ye, Shin-ichi Fujiwara, Nobuaki Kambe
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-Bu3)) (7) have been examined. Among them, the combined use of 2- and 3-iodothiophene with PhSK resulted in the formation of (Z)-Ar(H)CC(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‘)(PPh3)2 (1).