bisthiolation of terminal alkynes, K2S (potassium sulfide) and diaryliodoniumsalts for the assembly of functionalized (Z)‐1,2‐bis(arylthio)alkene derivatives has been accomplished for the first time. This unique observation features a broad substrate scope, excellent functional‐group tolerance, and high regioselectivity. Especially, an arylthiolate anion from diaryliodoniumsalts and potassium sulfide
Free Radical Addition of Thiophenol to 3-Substituted 1-Alkyne with or without Migration of the Substituents
作者:Hideyoshi Miyake、Kimiaki Yamamura
DOI:10.1246/bcsj.61.3752
日期:1988.10
Thiophenol reacts with 3-phenylthio- and 3-bromo-1-alkyne in the presence of radical initiator to give 1,2-bis(phenylthio)-1-alkene and 2-bromo-1-phenylthio-1-alkene.
RhH(PPh(3))(4) and 1,1'-bis(diphenylphosphino)ferrocene catalyze the regio- and stereoselective additions of diaryl disulfides and diaryldiselenides to 1-alkynes giving (Z)-1-arylseleno-2-arylthio-1-alkenes. The catalyst promotes the addition reaction of dibutyl disulfide and dibutyl diselenide to 1-octyne with a similar selectivity giving (Z)-1-butylseleno-2-butylthio-1-octene but with a lower catalytic
Novel transition-metal-catalyzed reactions of disulfides and diselenides with acetylenes are described. In the of tetrakis(triphenylphosphine)palladium(0), [Pd(PPh3)4], the (1) of diaryl disulfides and diselenides to terminal acetylenes 1 takes place stereoselectively to give high yields of (Z)-1,2-bis(arylthio)-1-alkenes 2 and (Z)-1,2-bis(arylseleno)-1-alkenes 3, respectively. A mechanistic proposal includes the following: (1) oxidative addition of (ArY)2 [Y = S, Se] to low-valent palladium species, (2) stereoselective cis-thiopalladation or cis-selenopalladation to acetylenes to form a cis-vinylpalladium intermediate, and (3) reductive elimination of the product with retention of the stereochemistry. When the reaction of diaryl disulfides and diselenides with terminal acetylenes is performed under the pressure of carbon monoxide, the carbonylative addition occurs to afford (Z)-1,3-bis(arylthio)-2-alken-1-ones 4 and (Z)-1,3-bis(arylseleno)-2-alken-1-ones 5, respectively. Carbon monoxide is regioselectively incorporated on the side of the terminal carbon of the acetylenes.
Palladium-Catalyzed Thioesterification of Alkynes with <i>O</i>-Methyl <i>S</i>-Phenyl Thiocarbonate