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Transfer Catalyst (transfer + catalyst)
Kinds of Transfer Catalyst Selected AbstractsChemInform Abstract: Efficient Aerobic Ruthenium-Catalyzed Oxidation of Secondary Alcohols by the Use of a Hybrid Electron Transfer Catalyst.CHEMINFORM, Issue 33 2010Eric V. Johnston Abstract An efficient biomimetic catalyst system for the title reaction is developed. [source] Design of Chiral Phase Transfer Catalyst with Conformationally Fixed Biphenyl Core: Application to Asymmetric Alkylation of Glycine Derivatives.CHEMINFORM, Issue 41 2007Yong-Gang Wang Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Kinetic Resolution of Protected ,-Amino Acid Derivatives by a Chiral O-Nucleophilic Acyl Transfer Catalyst.CHEMINFORM, Issue 31 2006Gregory T. Notte Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Kinetic Resolution of ,-Acetoxy N-Acyl Oxazolidinethiones by a Chiral O-Nucleophilic Acyl Transfer Catalyst.CHEMINFORM, Issue 4 2006Gregory T. Notte No abstract is available for this article. [source] Polyphenylene as an Electron Transfer Catalyst in Lithiation Processes.CHEMINFORM, Issue 47 2002Miguel Yus Abstract For Abstract see ChemInform Abstract in Full Text. [source] Syntheses and Properties of Fluorous Quaternary Phosphonium Salts that Bear Four Ponytails; New Candidates for Phase Transfer Catalysts and Ionic LiquidsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 12-13 2006Charlotte Emnet Abstract The fluorous tertiary phosphine [Rf6(CH2)2]3P [Rfn=CF3(CF2)n,1] and excess PhCH2Br, CH3(CH2)3OSO2CF3, or Rf6(CH2)2OSO2CF3 react (CF3C6H5, 45,110,°C) to give the phosphonium salts (PhCH2)[Rf6(CH2)2]3P+ Br, (2, 71,%), [CH3(CH2)3][Rf6(CH2)2]3P+ CF3SO3, (3, 65,%), or [Rf6(CH2)2]4P+ CF3SO3, (4, 83,%). The phosphines [Rf6(CH2)2]2[Rf8(CH2)2]P and [Rf8(CH2)2]3P are similarly elaborated with Rf6(CH2)2I, Rf8(CH2)2I, or Rf8(CH2)2Br (DMF, 115,°C) to [Rf8(CH2)2]4- x[Rf6(CH2)2]xP+ I, (x=3, 7; 2, 8; 1, 9; 0, 10) or [Rf8(CH2)2]4P+ Br, (80,60,%). The salts exhibit melting points between 110,°C and 43,°C, with lower values favored by less symmetrical cations, Rf6 segments, and triflate and bromide anions. Solubilities decrease in the solvent sequence CF3C6F5 (all salts at least moderately soluble, room temperature)>acetone>THF>CF3C6H5>CF3C6F11>CH3C6H5, Et2O, CH2Cl2, hexane (all salts insoluble at elevated temperatures); some appreciably increase upon heating. Partition coefficients are very biased towards fluorous phases (>93:<7). The salts can be quite efficient at extracting picrate from water into CF3C6F5 (97,86,% for 2, 4, 9, 10) or CF3C6H5 (85,66,% for 2 - 4), demonstrating their potential for phase transfer catalysis. A CF3C6F5 solution of Rf8(CH2)3I and aqueous NaCl react at 100,°C in the presence (but not the absence) of 9 to give Rf8(CH2)3Cl. [source] Contrast Performance in Catalytic Ability , New Cinchona Phase Transfer Catalysts for Asymmetric Synthesis of ,-Amino Acids.CHEMINFORM, Issue 23 2005Shanmugam Elango Abstract For Abstract see ChemInform Abstract in Full Text. [source] Liquid-Liquid-Liquid Phase Transfer Catalysis: A Novel and Green Concept for Selective Reduction of Substituted NitroaromaticsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 9 2005Ganapati Abstract The selective reduction of nitroaromatics to the corresponding amines is an important transformation since many aromatic amines exhibit biological activities and find a multitude of industrial applications, being intermediates for the synthesis of dyes, pharmaceuticals and agrochemicals. A variety of nitroaromatics dissolved in organic solvents was reduced by using aqueous sodium sulfide, and tetrabutylammonium bromide (TBAB) as the phase transfer catalyst by choosing appropriate concentrations which resulted in three immiscible liquid phases. Compared to L-L PTC, the L-L-L PTC offers much higher rates of reaction, better selectivities and repeated use of catalyst. The selectivities for the desired products were 100%. [source] A gemini amphiphilic phase transfer catalyst for dark singlet oxygenationJOURNAL OF PHYSICAL ORGANIC CHEMISTRY, Issue 7-8 2008Cédric Borde Abstract A new gemini surfactant phase transfer catalyst, namely diethyl-ether-,,,-bis-(dimethyldodecylammonium molybdate) codified as 12-EO-12-Mo, was prepared by anion exchange from the analogous gemini dichloride (12-EO-12-Cl2). The physico-chemical properties of these compounds such as Krafft temperature, critical micelle concentration, surface activity and binary water-surfactant behavior were compared and the influence of the molybdate counterion was examined. Though both compounds are highly hydrophilic, the cmc of 12-EO-12-Mo (0.4,mmol L,1) is about five times lower than of its dichloride analogue (2.2,mmol L,1). Moreover, 12-EO-12-Mo exhibits an additional cubic liquid crystal phase between 53 and 64,wt%. The usefulness of 12-EO-12-Mo as an amphiphilic phase transfer catalyst for the dark singlet oxygenation was demonstrated with the peroxidation of two typical organic substrates: ,-terpinene which reacts with 1O2 according to a [4,+,2] cycloaddition and the less reactive ,-citronellol, which provides two hydroperoxides according to the ene-reaction. 12-EO-12-Mo provides a simple reaction medium with only three components for the preparative peroxidation of hydrophobic substrates by chemically generated singlet oxygen. Copyright © 2008 John Wiley & Sons, Ltd. [source] Synthesis, Characterization, and Mechanism of Polymerization of Poly(but-2-ene sulfide),MACROMOLECULAR RAPID COMMUNICATIONS, Issue 15 2004Subramanian Sundarrajan Abstract Summary: The effect of structural factors on polymer formation versus cyclization is reported. The reaction of sodium sulfide with either 1,4-dibromobut-2-ene 1 or 1,4-dibromobutane 2 has been carried out in presence of a phase transfer catalyst and it was observed that the former yields polymer, whereas the latter gives cyclic and linear products. Interestingly, trans/cis isomerization takes place during the polymer formation from 1 and a plausible mechanism has also been discussed. The reaction mechanism for unsaturated compound 1 and saturated compound 2 is discussed here. [source] Facile Synthesis of 3-Substituted-1,2,3,4-tetrahydropyrido-[3,2- d]pyrimidine-2,4-dione on Poly(ethylene glycol)CHINESE JOURNAL OF CHEMISTRY, Issue 3 2008Feng-Ying XIANG Abstract An efficient and short route to synthesize pyrido[3,2- d]pyrimidinediones was achieved using poly(ethylene glycol) as a soluble polymeric support and phase transfer catalyst. The poly(ethylene glycol) (PEG) was reacted with 2,3-pyridinedicarboxylic anhydride to give PEG-bound ester 1, which was transformed into corresponding PEG-bound acyl azide 2. Then the PEG-supported acyl azide 2 was rearranged, reacted with a series of amines and spontaneously cycled to give product 5 in 84%,88% overall yields. [source] Chiral amino amides for the ruthenium(II)-catalyzed asymmetric transfer hydrogenation reaction of ketones in waterCHIRALITY, Issue 1 2010Jincheng Mao Abstract The chiral amino amide 3 was derived from L -proline and used for the [RuCl2(p -cymene)]2 -catalyzed asymmetric transfer hydrogenation of prochiral ketones performed in water. Moderate to good chemical selectivities (up to 95% yield) and enantioselectivities (up to 90% ee) were obtained in the presence of 2 mol % of TBAB (n -Bu4NBr) as the phase transfer catalyst. Chirality, 2010. © 2009 Wiley-Liss, Inc. [source] Synthesis, Crystal Structure of Co(II)(6-methoxybenzothiazole- 2-carboxylate)2(DMF)2 and Its Application to Carbonylation of Benzyl ChlorideCHINESE JOURNAL OF CHEMISTRY, Issue 1 2010Bin Zhang Abstract A new complex, Co(MBTC)2(DMF)2 (MBTC=6-methoxybenzothiazole-2-carboxylate, DMF=N,N -dime- thylformamide), was synthesized in DMF solution and characterized by single crystal X-ray diffraction analysis. Using the cobalt complex as catalyst, phenylacetic acid was prepared by the carbonylation of benzyl chloride with carbon monoxide (0.1 MPa). The effects of solvents, phase transfer catalysts and temperature on the reactions were investigated. The yield of phenylacetic acid was higher than 90% in optimized condition. [source] | ||||||||||