2132-59-4Relevant articles and documents
Stereoselective synthesis of novel benzoins catalysed by benzaldehyde lyase in a gel-stabilised two-phase system
Hischer, Tanja,Gocke, D?rte,Fernández, María,Hoyos, Pilar,Alcántara, Andrés R.,Sinisterra, José V.,Hartmeier, Winfried,Ansorge-Schumacher, Marion B.
, p. 7378 - 7383 (2005)
Asymmetric benzoin condensation was performed using recombinant benzaldehyde lyase (BAL) from Pseudomonas fluorescens Biovar I. To enable the conversion of hydrophobic substrates, the enzyme was entrapped in polyvinyl alcohol and suspended in hexane. Compared to the reported application of the biocatalyst in an aqueous phase containing 20% DMSO, the productivity of the resulting gel-stabilised two-phase system was 3-fold better. The entrapment process had an efficiency of >90%, no enzyme or cofactor was lost during reaction or storage. The entrapped enzyme was stable in hexane for 1 week at 4°C and more than 1 month at -20°C. Without preceding optimisation the novel benzoins (R)-1,2-di(3-furanyl)-2-hydroxyethanone, (R)-2-hydroxy-1,2-di(3- thienyl) ethanone, (R)-1,2-di(4-ethoxyphenyl)-2-hydroxyethanone, (R)-1,2-di(3-ethoxyphenyl)-2-hydroxyethanone, (R)-2-hydroxy-1,2-di(3-tolyl) ethanone, and (R)-1,2-di(benzofuran-2-yl)-2-hydroxyethanone were prepared with yields up to 31.8% and enantiomeric excess >99%.
Galactose oxidase model: Biomimetic enantiomer-differentiating oxidation of alcohols by a chiral copper complex
Alamsetti, Santosh Kumar,Mannam, Sreedevi,Mutupandi, Pandi,Sekar, Govindasamy
supporting information; experimental part, p. 1086 - 1090 (2009/10/23)
An enantiopure analogue of galactose oxidase (GO) was synthesized from an easily and readily available source with a similar activity of GO's in primary alcohol oxidation and enantioselective catalysts for aerobic oxidative kinetic resolution (AORK) of racemic secondary alcohols. Enantiopure (R)-binam was treated with Cu(OTf)2 in toluene at room temperature for one hour to give a (R)-binam-Cu complex. It is found that enantiopure benzoin is an important intermediate in the synthesis of a potent anticancer agent and can been synthesized by enzymatic hydrolysis with benzaldehyde lyase (BAL). The S enantiomer of the racemate is oxidized faster to the corresponding benzil and the slow-reacting R enentiomer of benzoin is recovered in an enantiomerically enriched form. It is also observed that ortho substitution reduces the rate of reaction, while a reduced enentioselectivity is observed in case of ortho-substituted benzoin.
Triphenylamine-modified quinoxaline derivatives as two-photon photoinitiators
Cao, Xingbo,Jin, Feng,Li, Ying-Feng,Chen, Wei-Qiang,Duan, Xuan-Ming,Yang, Lian-Ming
experimental part, p. 1578 - 1582 (2009/10/30)
Two new chromophores, triphenylamine-modified quinoxaline (TPAQ) and benzoquinoxaline (TPABQ), were synthesized, and their linear spectroscopy and two-photon absorption properties were investigated. For comparison, 4-ethoxyphenyl-substituted quinoxaline (EOQ) and benzoquinoxaline (EOBQ) were prepared. The results showed that TPAQ possesses a high fluorescence quantum yield and a high δ2PA value of >160 GM in the laser light wavelength range of 780-820 nm, and is superior to most common benzil-type compounds as a photoinitiator in two-photon initiated polymerization. The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2009.
