53636-17-2Relevant academic research and scientific papers
Simple one-pot process for the bioresolution of tertiary amino ester protic ionic liquids using subtilisin
Brossat, Maude,Moody, Thomas S.,Taylor, Stephen J.C.,Wiffen, Jonathan W.
experimental part, p. 2112 - 2116 (2010/02/28)
An efficient hydrolase-catalyzed bioresolution of tertiary amino ester protic ionic liquids has been demonstrated. Protic ionic liquids have been prepared in one step from the corresponding tertiary amino alcohols by treatment with butyric anhydride. Afte
Electroreductive generation of (S)-(+)-N,N-dimethyl-2-(hydroxymethyl)- pyrrolidinium mercury compound for enantioselective synthesis of 2-amino-1-alkyl/aryl ethanols
Yadav, Ashok K.,Manju, Meera
, p. 2770 - 2772 (2008/04/18)
(S)-(+)-N, N - Dimethyl-2-(hydroxymethyl)-pyrrolidinium (DMHP +)-mercury compound mediated enantioselective reduction of aminomethyl alkyl/aryl ketones in dimethylformamide-2-propanol (9:1) has been carried out using tetrabutylammonium tetrafluoroborate as a supporting electrolyte. The products viz. 2-amino-1-alkyl/aryl ethanols have been obtained in good yield (68-92%) with 35-91% optical purity and have been assigned (S)-configuration. The pinacol (racemic/meso) derivatives are also isolated as minor products (yield 5-20%) via dimerization of radical anion followed by protonation.
Synthesis of optically active methadones, LAAM and bufuralol by lipase-catalysed acylations
Hull, Jonathan D.,Scheinmann, Feodor,Turner, Nicholas J.
, p. 567 - 576 (2007/10/03)
(R)- and (S)-Methadones and levo-α-acetylmethadol (LAAM) have been synthesised starting from lipase-catalysed acylation of dimethylaminopropan-2-ol. An approach to the synthesis of (R)-bufuralol is also presented.
Process for preparing optically active secondary alcohols having nitrogenous or oxygenic functional groups
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, (2008/06/13)
A process for preparing optically active secondary alcohols of the general formula (3), [wherein R1 is linear lower alkyl, an aromatic ring group, or the like; A is CH2NR2R3 or the like; n is an integer of 0 to 2; and * represents an asymmetric carbon atom] by asymmetrically hydrogenating a ketone compound of the general formula (1) having nitrogenous or oxygen functional group at any of the a-, β- and γ-positions, with selectivity among functional groups by the use of a ruthenium/optically active bidentate phosphine/diamine complex as the catalyst in the presence of hydrogen alone or together with a base. The optically active secondary alcohols obtained by the process are useful as drugs and intermediates for the preparation of drugs.
Process for the preparation of optically active methadones in high enantiomeric purity
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, (2008/06/13)
PCT No. PCT/GB97/01441 Sec. 371 Date Apr. 9, 1999 Sec. 102(e) Date Apr. 9, 1999 PCT Filed May 27, 1997 PCT Pub. No. WO97/45551 PCT Pub. Date Dec. 4, 1997A method of preparing optically active methadones comprises an enzymatic process for the resolution of 1-dialkyl-amino-2-propanol and conversion of the enantiomers to the optically active methadones in high enantiomeric purity.
Cationic BINAP-Ru(II) Halide Complexes: Highly Efficient Catalysts for Stereoselective Asymmetric Hydrogenation of α- and β-Functionalized Ketones
Mashima, Kazushi,Kusano, Koh-hei,Sato, Naomasa,Matsumura, Yoh-ichi,Nozaki, Kyoko,et al.
, p. 3064 - 3076 (2007/10/02)
Cationic ruthenium-BINAP complexes 5, 7, and 10 of the formula Y, where X = Cl, Br, I; Y = Cl, Br, I, BF4, B(C6H5)4; arene = benzene, p-cymene, ethyl benzoate, and their enantiomers have been prepared by the reaction of arene-ruthenium halide complexes 4, 6, and 9 with (S)-BINAP or (R)-BINAP.Structures of the complexes were established by spectroscopy, conductivity, and a single-crystal X-ray analysis (5d: orthorhombic, P21212; a=20.141(2) Angstroem, b=18.504(1) Angstroem, c=12.241(1) Angstroem, V=4562.0(7) Angstroem3, Z=4, R=0.078 for unique 4177 reflections).BINAP derivatives with various substituents at the para and meta positions of four phenyl rings on phosphorus atoms and their cationic Ru(II) complexes have also been synthesized.These BINAP-Ru(II) complexes have been used as catalysts for the asymmetric hydrogenation of various unsaturated organic compounds such as α- and β-keto esters, allylic alcohols, and α,β-unsaturated carboxylic acids in excellent diastereo- and/or enantioselectivities.Catalytic activities and stereoselectivities depend highly on reaction conditions such as solvent, temperature, and additives.Variation of halogen ligands bound to ruthenium atom and substituents on four phenyl rings of BINAP also have exerted remarkable effects on the efficiency of the catalysis.Asymmetric hydrogenation of methyl (+/-)-2-(benzamidomethyl)-3-oxobutanoate catalyzed by the species derived from 9c and 3,5-(t-Bu)2-BINAP afforded the corresponding syn-(2S,3R)-17 in 98percent de and 99percent ee.
An Inversion of Chirality at a Chiral Micelle Surface
Radley, K.,Cattey, H.
, p. 167 - 176 (2007/10/02)
Two chiral quaternary ammonium bromide detergents S-1,2- and S-2,1-N-hexadecyl-N,N-dimethyl propanol bromide with the same S molecular configuration which are constituent isomers have been synthesised.They were used to prepare Amphiphillic Cholesteric Liquid Crystal (ACLC) samples where the molecular stereochemistry in respect to the micelle surface was inverted in respect to one another.Concomitant inversions in the sign of the optical rotation were found using the polarising microscope.Laser duffraction was used to determine the twists in these ACLC samples, which were found to be exceptionally small.The small twists were thought to be the result of the hydroxyl group in the chiral amphiphillic head group pushing the chiral centres apart. - Keywords: Amphiphillic liquid crystal, chiral micelle surface, cholesteric liquid crystal
Diphenyloxazaborolidine a new catalyst for enantioselective reduction of ketones
Quallich, George J.,Woodall, Teresa M.
, p. 4145 - 4148 (2007/10/02)
A variety of ketones can be reduced in high enantioselectivity with the oxazaborolidines derived from commercially available erythro aminodiphenylethanol.
p-Hydroxymethadone: Synthesis, Crystal Structure and CD Properties
Brine, George A.,Boldt, Karl G.,Prakash, Doriswamy,Kotchmar, Dennis J.,Bondeson, Virginia C.,et al.
, p. 1809 - 1814 (2007/10/02)
Alkylation of 2-chloro-N,N-dimethylpropylamine 2 with the lithium salt derived from 2-(p-methoxyphenyl)-2-phenylacetonitrile 1 afforded a mixture of p-methoxymethadone nitrile 3 and p-methoxyisomethadone nitrile 4.The nitriles were separated chromatographically and the amino nitrile 3 was converted subsequently into the diastereoisomeric p-hydroxymethadone 8 hydrochlorides.Careful recrystallization afforded a separation of the (4RS,6RS)- and (4RS,6SR)-p-hydroxymethadone hydrochlorides.Repetition of the synthesis using (R)-2-chloro-N,N-dimethylpropylamine, derived in three steps from (S)-dilactide 9, yielded the (4S,6S)- and (4R,6S)-p-hydroxymethadone hydrochlorides, which were also separated by fractional crystallization.The absolute configuration of the products was verified by X-ray crystallography.The (4R,6S) salt exhibited a more intense Cotton effect than (S)-methadone hydrochloride while the (4S,6S) salt showed a less intense Cotton effect and less fine structure in the λ 260-275 nm range.
