38003-42-8Relevant academic research and scientific papers
Promoters for Pd-catalyzed methoxycarbonylation of vinyl acetate
Shuklov, Ivan A.,Dubrovina, Natalia V.,Schulze, Joachim,Tietz, Wolfgang,Kuehlein, Klaus,Boerner, Armin
experimental part, p. 66 - 75 (2012/03/11)
A study on the influence of acidic and non-acidic promoters for Pd(PPh 3)-catalyzed methoxycarbonylation of vinyl acetate was conducted in order to find an efficient protocol for the synthesis of methyl O-acetyl lactate. Besides known promoters also some new catalytic systems were tested. Aluminium triflate is the most active additive. ARKAT-USA, Inc.
The methoxycarbonylation of vinyl acetate catalyzed by palladium complexes of [1,2-phenylenebis(methylene)]bis[di(tert-butyl)phosphine]
Rucklidge, Adam J.,Morris, George E.,Slawin, Alexandra M. Z.,Cole-Hamilton, David J.
, p. 1783 - 1800 (2007/10/03)
Palladium complexes of [1,2-phenylenebis(methylene)]bis[di(tert-butyl) phosphine] (1) catalyze the methoxycarbonylation of vinyl acetate (=ethenyl acetate) in the presence of methanesulfonic acid (Scheme 1). High selectivities to ester products can be obtained if free phosphine ligand is in excess over the amount of added acid (Table 1). Selectivities to methyl 2-acetoxypropanoate, a precursor to lactate esters, can be as high as 3.6:1 at low temperature and pressure (Table 2). Replacing tBu by iPr groups leads to less-active catalysts and lower selectivities to the branched product. Replacing the phenylene moiety by a naphthalenediyl moiety also gives lower activity, but with similar selectivity to the phenylene-based analogues. Linear hydrocarbon-chain linkers as the backbone instead of the phenylenebis(methylene) linker leads to poor catalysis, except for a propane-1,3-diyl linker, which gives good rates but poor branched selectivity (Table 5). The effect of different reaction conditions on the catalysis is discussed. The syntheses of the new xylene-based diphosphines 2-5 with one to four iPr groups replacing the tBu groups at the P-atoms of 1 and of the ligands 6 and 7 based on 1,2- and 2,3-dimethylnaphthalene are also described (Schemes 2 and 3).
Highly active and selective palladium catalyst for hydroesterification of styrene and vinyl acetate promoted by polymeric sulfonic acids
Ooka, Hirohito,Inone, Tsutomu,Itsuno, Shinichi,Tanaka, Masato
, p. 1173 - 1175 (2007/10/03)
Highly efficient, selective and recyclable palladium catalyst systems for hydroesterification of styrene and vinyl acetate were realized by using 1,2-bis(di-tert-butylphosphinomethyl)benzene as ligand and polymeric sulfonic acids of limited SO3H loadings as promoter. The Royal Society of Chemistry 2005.
