157239-52-6Relevant academic research and scientific papers
Hydroesterification of styrene derivatives catalyzed by an acidic resin supporting palladium complexes
He, Zhenhong,Hou, Zhenshan,Luo, Yanping,Dilixiati, Yierxiati,Eli, Wumanjiang
, p. 1092 - 1103 (2014)
Pd-TPPTS-OTPPTS (denoted as Pd-P-OP, where TPPTS was the sodium salt of tri(m-sulfophenyl)phosphine and OTPPTS was the oxidized form of TPPTS) complexes supported on acidic resins (denoted as Pd-P-OP/resin) were prepared and employed as versatile heterogeneous catalysts for the hydroesterification of vinyl-aromatics with alcohols. The catalysts were characterized by the methods of FT-IR, XPS, N2 physisorption, XRD, TGA, SEM and 31P NMR. According to the 31P NMR results, there was a weak coordination between OTPPTS and the Pd sites. Consequently, OTPPTS was a weak ligand to the Pd sites and thus dissociated easily, acting as a protective agent of the vacant coordination site of the Pd metal sites, which allowed the substrates more access to the metal sites. In the hydroesterification of styrene, the distribution of the branched and linear esters was remarkably impacted by adding an appropriate amount of OTPPTS and the acidic resin supports. A high yield and excellent selectivity towards the branched ester were obtained when OTPPTS and TPPTS were used in equimolar amounts under optimized reaction conditions. The generality and recyclability of the catalyst for the hydroesterification of vinyl-aromatics were also examined. In addition, the poisoning and hot filtration tests indicated that Pd(0) acted as the active species in a truly heterogeneous way. A Pd-hydride mechanism was proposed for the hydroesterification over the Pd-P-OP/LSI-600 catalyst. This journal is the Partner Organisations 2014.
Direct Lewis Acid Catalyzed Conversion of Enantioenriched N-Acyloxazolidinones to Chiral Esters, Amides, and Acids
Stevens, Jason M.,Parra-Rivera, Ana Cristina,Dixon, Darryl D.,Beutner, Gregory L.,Delmonte, Albert J.,Frantz, Doug E.,Janey, Jacob M.,Paulson, James,Talley, Michael R.
, p. 14245 - 14261 (2019/01/03)
The identification of Yb(OTf)3 through a multivariable high-throughput experimentation strategy has enabled a unified protocol for the direct conversion of enantioenriched N-acyloxazolidinones to the corresponding chiral esters, amides, and carboxylic acids. This straightforward and catalytic method has shown remarkable chemoselectivity for substitution at the acyclic N-acyl carbonyl for a diverse array of N-acyloxazolidinone substrates. The ionic radius of the Lewis acid catalyst was demonstrated as a key driver of catalyst performance that led to the identification of a robust and scalable esterification of a pharmaceutical intermediate using catalytic Y(OTf)3.
Novel ruthenium-catalyst for hydroesterification of olefins with formates
Profir, Irina,Beller, Matthias,Fleischer, Ivana
supporting information, p. 6972 - 6976 (2014/10/15)
An alternative ruthenium-based catalyst for the hydroesterification of olefins with formates is reported. The good activity of our system is ensured by the use of a bidentate P,N-ligand and ruthenium dodecacarbonyl. A range of formates can be used for selective alkoxycarbonylation of aromatic olefins. In addition, the synthesis of selected aliphatic esters is realized. The proposed active ruthenium complex has been isolated and characterized. This journal is the Partner Organisations 2014.
Improvements of enzyme activity and enantioselectivity in lipase-catalyzed alcoholysis of (R,S)-azolides
Wu, An-Chi,Wang, Pei-Yun,Lin, Yi-Sheng,Kao, Min-Fang,Chen, Jin-Ru,Ciou, Jyun-Fen,Tsai, Shau-Wei
experimental part, p. 235 - 241 (2010/11/04)
With Candida antarctica lipase B (CALB)-catalyzed alcoholysis of (R,S)-naproxenyl 1,2,4-triazolide at the optimal conditions (i.e. anhydrous MTBE as the solvent, and methanol as the acyl acceptor at 45°C) as the model system, the enzyme enantioselectivity
Palladium complexes of bulky ortho-trifluoromethylphenyl-substituted phosphines: Unusually regioselective catalysts for the hydroxycarbonylation and alkoxycarbonylation of alkenes
Grabulosa, Arnald,Frew, Jamie J.R.,Fuentes, José A.,Slawin, Alexandra M.Z.,Clarke, Matthew L.
experimental part, p. 18 - 25 (2010/12/20)
The reactions of the very bulky phosphine ligands containing both tert-butyl and ortho-trifluoromethylphenyl substituents with [PdCl 2(PhCN)2] have been studied, in order to assess the impact of steric and electronic effects on a ligand's coordination ability. The palladium complexes of tert-butyl(ortho-trifluoromethylphenyl)methyl phosphine and tert-butyl(ortho-trifluoromethylphenyl)(n-butyl)phosphine were characterised by X-ray crystallography and shown to be good precatalysts for the hydroxy- and alkoxycarbonylation of alkenes relative to Pd complexes of tricyclohexylphosphine and triphenylphosphine. A notable feature of Pd complexes of tert-butyl(ortho-trifluoromethylphenyl)methyl phosphine is significantly enhanced regioselectivity relative to previous state-of-the-art catalysts in the hydroxycarbonylation of styrene, even if lithium chloride co-catalysts are not used. These catalysts derived from large cone angle ligands consistently give higher regioselectivity in the alkoxycarbonylation of styrene using ethanol, n-propanol, and i-propanol as nucleophiles. These Pd complexes are also active in the Suzuki coupling of activated aryl chlorides, and in both carbonylation and Suzuki reactions, tert-butyl(ortho-trifluoromethylphenyl)methyl phosphine gives more productive catalysts than its bulkier analogues.
Highly enantioselective hydroxycarbonylation and alkoxycarbonylation of alkenes using dipalladium complexes as precatalysts
Konrad, Tina M.,Fuentes, Jose A.,Slawin, Alexandra M. Z.,Clarke, Matthew L.
supporting information; experimental part, p. 9197 - 9200 (2011/02/28)
Joined at Pd: Novel palladium catalysts like 1, in which the planar-chiral phosphine acts as a bridging ligand, have been developed. These dimetallic complexes are highly enantioselective catalysts in the hydroxycarbonylation of alkenes, a reaction that has proven problematic over the years. PTSA=para-toluenesulfonic acid. Copyright
Resolution of (RS)-2-phenylpropanoic acid by enantioselective esterification with dry microbial cells in organic solvent
Gandolfi, Raffaella,Gualandris, Roberto,Zanchi, Chiara,Molinari, Francesco
, p. 501 - 504 (2007/10/03)
The microbial direct esterification of racemic 2-phenyl-1-propanoic acid with ethanol by lyophilized mycelium of Aspergillus oryzae MIM and Rhizopus oryzae CBS 112.07 in organic solvents has been investigated. Dry cells of Rhizopus oryzae CBS 112.07 gave the (R)-ethyl ester with high enantiomeric excess (>97%) when the biotransformation was carried out in heptane or pentadecane. Dry mycelium of Aspergillus oryzae MIM furnished the ethyl ester of (S)-(+)-2-phenylpropanoic acid with 90% enantiomeric excess when used in toluene in a temperature range of 20-40°C.
Lipase catalyzed resolution of chiral acids or alcohols using mixed carboxylic-carbonic anhydrides
Guibe-Jampel, Eryka,Chalecki, Zbigniew,Bassir, Mohamed,Gelo-Pujic, Mirjana
, p. 4397 - 4402 (2007/10/03)
Mixed carboxylic-carbonic anhydrides are efficient irreversible acyl transfer reagents for lipase catalyzed esterification in organic media, and can be used for the resolution of chiral carboxylic acids or alcohols.
Lipase catalyzed resolution of chiral acids using their mixed carboxylic carbonic anhydrides
Guibe-Jampel, Eryka,Bassir, Mohamed
, p. 421 - 422 (2007/10/02)
Mixed carboxylic-carbonix anhydrides are efficient irreversible acyl transfer reagents for lipase-catalyzed esterification in organic media, and can be used for the resolution of chiral carboxylic acids.
