The reaction of propargylic alcohols with diaryl disulfides and carbon monoxide in the presence of tetrakis(triphenylphosphine)palladium leads to a novel thiolative lactonization to afford beta-(arylthio)-alpha,beta-unsaturated lactones in moderate to good yields. Similar conditions can be employed with homopropargylic alcohols, giving the corresponding delta-lactones with a beta-arylthio group successfully
The polymer-supported recyclable palladium catalyst was prepared for stereoselective diaryl disulphides addition to terminal alkynes with high yields. The 96-98% product purity was achieved after filtering the polymer-supported catalyst without special purification procedure.
NMR approach for the identification of dinuclear and mononuclear complexes: The first detection of [Pd(SPh)2(PPh3)2] and [Pd2(SPh)4(PPh3)2] – The intermediate complexes in the catalytic carbon–sulfur bond formation reaction
作者:Valentine P. Ananikov、Sergey S. Zalesskiy、Vadim V. Kachala、Irina P. Beletskaya
DOI:10.1016/j.jorganchem.2010.10.012
日期:2011.1
analyzed the nature of palladium complexes in the catalytic system for selective carbon–sulfur bond formation via the addition of S–S and S–H bonds to alkynes. For the first time the mononuclear and dinuclear palladium complexes were clearly detected by DOSY NMR under the catalytic conditions. It was demonstrated that the concentration of these palladium complexes strongly depends on the amount of
Addition of diaryl disulfides to terminal alkynes catalysed by an MCM-41-supported bidentate phosphine palladium(0) complex
作者:Jianying Li、Jun Liu、Mingzhong Cai
DOI:10.3184/030823409x12526892025829
日期:2009.10
2-bis(arylthio)-substituted alkenes have been conveniently synthesised in high yields by the stereoselective addition of diaryl disulfides to terminal alkynes catalysed by an MCM-41-supported bidentate phosphinepalladium(0) complex. This polymeric palladium catalyst can be recovered and reused many times without any loss of activity.
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.