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10-Undecenoate

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Laureano Oliveros – 1st expert on this subject based on the ideXlab platform

  • Mixed cellulose-derived benzoates bonded on allylsilica gel as HPLC chiral stationary phases: influence of the introduction of an aromatic moiety in the fixation substituent
    Tetrahedron-asymmetry, 2003
    Co-Authors: Jordi Garcés, Laureano Oliveros, Pilar Franco, Cristina Minguillón

    Abstract:

    Abstract Several mixed alkenoxybenzoyl/benzoates and 10-undecenoyl/benzoates of cellulose were fixed onto allylsilica gel by the radical coupling of double bonds. The introduction of an aromatic group in the fixation substituent modifies the chiral recognition ability of the resulting chiral stationary phases (CSPs) in comparison with the 10-Undecenoate/benzoate cellulose derivatives. Better enantioselectivity values are achieved when the electronic and geometric characteristics of both substituents, fixating and derivatizing, are similar.

  • First synthesis of the two enantiomers of α‐methyldiphenylalanine [(αMe)Dip] by HPLC resolution
    Chirality, 2001
    Co-Authors: Soledad Royo, Laureano Oliveros, Ana I. Jiménez, Pilar López, Carlos Cativiela

    Abstract:

    A strategy for the preparation of enantiomerically pure (R)- and (S)-α-methyldiphenylalanine, constrained phenylalanine analogs, is described. A racemic precursor was prepared in high yield from easily available starting products and subjected to HPLC resolution on a noncommercial chiral stationary phase. More than 600 mg of each enantiomer was isolated in optically pure form by using a 150 × 20 mm ID column containing mixed 10-Undecenoate/3,5-dimethylphenylcarbamate of cellulose covalently bonded to allylsilica gel and a mixture of n-hexane/2-propanol/acetone as the mobile phase. Chirality 14:39–46, 2002. © 2002 Wiley-Liss, Inc.

  • Efficient access to all four stereoisomers of phenylalanine cyclopropane analogues by chiral HPLC
    Chirality, 1999
    Co-Authors: Carlos Cativiela, María D. Díaz-de-villegas, Ana I. Jiménez, Pilar López, Michel Marraud, Laureano Oliveros

    Abstract:

    : Bonded polysaccharide-derived chiral stationary phases were found to be useful for the preparation of the four stereoisomers of the cyclopropane analogue of phenylalanine (c(3)Phe) as well as for the direct determination of the enantiomeric purity of c(3)Phe derivatives by HPLC. Three chiral stationary phases, consisting of cellulose and amylose derivatives chemically bonded on allylsilica gel, were tested. The mixed 10-Undecenoate/3, 5-dimethylphenylcarbamate of cellulose, 10-Undecenoate/3, 5-dimethylphenylcarbamate of amylose and 10-Undecenoate/p-methylbenzoate of cellulose were the starting polysaccharide derivatives for CSP-1, CSP-2, and CSP-3, respectively. Using mixtures of n-hexane/chloroform/2-propanol as mobile phase on a semi-preparative column (150 mm x 20 mm ID) containing CSP-2, we separated about 1.7 g of racemic cis-methyl 1-tert-butoxycarbonylamino-2-phenylcyclopropanecarboxylate (cis-6) and 1.2 g of racemic trans-methyl-1-tert-butoxycarbonylamino-2-phenylcycloprop-anecarboxyl ate (trans-6) by successive injections. Copyright 1999 Wiley-Liss, Inc.

Cristina Minguillón – 2nd expert on this subject based on the ideXlab platform

  • Mixed cellulose-derived benzoates bonded on allylsilica gel as HPLC chiral stationary phases: influence of the introduction of an aromatic moiety in the fixation substituent
    Tetrahedron-asymmetry, 2003
    Co-Authors: Jordi Garcés, Laureano Oliveros, Pilar Franco, Cristina Minguillón

    Abstract:

    Abstract Several mixed alkenoxybenzoyl/benzoates and 10-undecenoyl/benzoates of cellulose were fixed onto allylsilica gel by the radical coupling of double bonds. The introduction of an aromatic group in the fixation substituent modifies the chiral recognition ability of the resulting chiral stationary phases (CSPs) in comparison with the 10-Undecenoate/benzoate cellulose derivatives. Better enantioselectivity values are achieved when the electronic and geometric characteristics of both substituents, fixating and derivatizing, are similar.

  • Carbamates of cellulose bonded on silica gel: Chiral discrimination ability as HPLC chiral stationary phases
    Chirality, 1998
    Co-Authors: Laureano Oliveros, Antonio Senso, Pilar Franco, Cristina Minguillón

    Abstract:

    Four cellulose mixed 10-Undecenoate/carbamate derivatives, simultaneously bearing 10-undecenoyl and variously substituted phenylaminocarbonyl groups, were chemically bonded on allylsilica gel. The study of the effect of these substitutions on the performance of the resulting chiral supports, and a comparison with the recently described 10-Undecenoate/3,5-dimethylphenylcarbamate derivative, are presented. In this study heptane/2-propanol or heptane/chloroform mixtures were used as mobile phases. Chirality 10:283–288, 1998. © 1998 Wiley-Liss, Inc.

  • Solvent versatility of bonded cellulose-derived chiral stationary phases for high-performance liquid chromatography and its consequences in column loadability
    Journal of Chromatography A, 1998
    Co-Authors: Pilar Franco, Cristina Minguillón, Laureano Oliveros

    Abstract:

    The chromatographic behaviour of a 10-Undecenoate/3,5-dimethylphenylcarbamate of cellulose bonded on allylsilica gel is tested using four organic mobile-phase modifiers (2-propanol, chloroform, tetrahydrofuran and ethyl acetate). The advantages of the broad choice of solvents offered by this kind of chiral stationary phases and their resistance are discussed. The loadability of the column and its dependence both on the racemate to be resolved and on the solvent used as mobile phase are also discussed.

Michael A. R. Meier – 3rd expert on this subject based on the ideXlab platform

  • Catalytic transesterification of cellulose in ionic liquids: Sustainable access to cellulose esters
    , 2020
    Co-Authors: Alexander M. Schenzel, Andrea Hufendiek, Christopher Barner-kowollik, Michael A. R. Meier

    Abstract:

    Catalytic transesterifications of cellulose were studied under homogeneous conditions using the ionic liquid 1-butyl-3-methylimidazolium chloride (BMIMCl) as a solvent. Cellulose was thus efficiently converted into cellulose esters employing various methyl esters and 10 mol% of 1,5,7-triazabicyclo[4.4.0]dec-5- ene (TBD) as catalyst. 1H NMR analysis of the products revealed up to 2.3 turnovers of the methyl esters per catalyst molecule, leading to degrees of substitution (DS) of up to 0.69. Although a comparatively low turnover number (TON) is observed, the developed methodology represents the first successful homogeneous catalytic reaction on cellulose. Furthermore, the new method is an important step forward in terms of sustainability, since the BMIMCl-DMSO mixture can be recycled and reused for the reaction, and toxic and corrosive chemicals commonly employed for cellulose esterification (such as anhydrides, acid chlorides and bromides, organic bases, all in overstoichiometric amounts) are avoided. To demonstrate the versatility of this transesterification, an aromatic (cellulose benzoate), an aliphatic (cellulose butyrate), and a fatty acid containing cellulose ester (cellulose 10-Undecenoate) were prepared. Additionally, cellulose 10-Undecenoate was successfully used for thiol-ene grafting onto reactions employing two thiols for efficient thiol-ene addition reactions. This journal is © the Partner Organisations 2014.

  • Catalytic Oxyfunctionalization of Methyl 10‐undecenoate for the Synthesis of Step‐Growth Polymers
    Macromolecular Chemistry and Physics, 2017
    Co-Authors: Marc Von Czapiewski, Michael A. R. Meier

    Abstract:

    An efficient synthesis strategy for the preparation of two renewable polyesters and one renewable polyamide via catalytic oxyfunctionalization of methyl 10-Undecenoate, a castor oil derived platform chemical, is described. The keto-fatty acid methyl ester (keto-FAME) is synthesized applying a cocatalyst-free Wacker oxidation process using a high-pressure reactor system. For this purpose, catalytic amounts of palladium chloride are used in the presence of a dimethylacetamide/water mixture and molecular oxygen as sole reoxidant. The thus derived AB monomers (hydroxy-esters, amine-ester) are synthesized from the obtained keto-FAME through Baeyer–Villiger oxidation and subsequent transesterification, reduction, or reductive amination, respectively. The resulting AB step-growth monomers are then studied in homopolymerizations using 1,5,7-triazabicyclo[4.4.0]dec-5-ene, DBU, and titanium(IV) isopropoxide as transesterification catalyst, yielding polymers with molecular weights (Mn) up to 15 kDa. The polyesters and the polyamide are carefully characterized by FTIR, SEC, 1H-NMR spectroscopy, and differential scanning calorimetry analysis.

  • Catalytic transesterification of cellulose in ionic liquids: sustainable access to cellulose esters
    Green Chemistry, 2014
    Co-Authors: Alexander M. Schenzel, Andrea Hufendiek, Christopher Barner-kowollik, Michael A. R. Meier

    Abstract:

    Catalytic transesterifications of cellulose were studied under homogeneous conditions using the ionic liquid 1-butyl-3-methylimidazolium chloride (BMIMCl) as a solvent. Cellulose was thus efficiently converted into cellulose esters employing various methyl esters and 10 mol% of 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) as catalyst. 1H NMR analysis of the products revealed up to 2.3 turnovers of the methyl esters per catalyst molecule, leading to degrees of substitution (DS) of up to 0.69. Although a comparatively low turnover number (TON) is observed, the developed methodology represents the first successful homogeneous catalytic reaction on cellulose. Furthermore, the new method is an important step forward in terms of sustainability, since the BMIMCl–DMSO mixture can be recycled and reused for the reaction, and toxic and corrosive chemicals commonly employed for cellulose esterification (such as anhydrides, acid chlorides and bromides, organic bases, all in overstoichiometric amounts) are avoided. To demonstrate the versatility of this transesterification, an aromatic (cellulose benzoate), an aliphatic (cellulose butyrate), and a fatty acid containing cellulose ester (cellulose 10-Undecenoate) were prepared. Additionally, cellulose 10-Undecenoate was successfully used for thiol–ene grafting onto reactions employing two thiols for efficient thiol–ene addition reactions.