- Candida Rugosa lipase-catalyzed kinetic resolution of β-hydroxy- β-arylpropionates and δ-hydroxy-δ-aryl-β-oxo-pentanoates
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A simple and convenient method was reported for the preparation of optically active β-hydroxy-β-arylpropionates, δ-hydroxy-δ- aryl-β-oxo-pentanoates and their butyryl derivatives via CRL-catalyzed hydrolysis. The optically active products are potential precursors of some chiral pharmaceuticals and natural products.
- Xu, Chengfu,Yuan, Chengye
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p. 2169 - 2186
(2007/10/03)
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- Pd-catalyzed kinetic resolution of benzylic alcohols: A practical synthesis of (R)-tomoxetine and (S)-fluoxetine hydrochlorides
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A convenient synthetic route to (R)-tomoxetine hydrochloride (90% ee) and (S)-fluoxetine hydrochloride (84% ee) is described. (S)-3-Phenyl-3-hydroxypropyl p-toluenesulphonate, the key intermediate, is obtained by the oxidative kinetic resolution of the corresponding racemic 3-phenyl-3-hydroxypropyl p-toluenesulphonate using (-)-sparteine/Pd(II)/O2 (1 atm) catalytic system.
- Ali, Iliyas Sayyed,Sudalai, Arumugam
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p. 5435 - 5436
(2007/10/03)
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- Hydrolases in organic synthesis: Preparation of enantiomerically pure compounds
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Esterhydrolases (Esterases, Lipases) are highly (chemo-, regio- and enantio-) selective biocatalysts for the transformation of racemic and achiral substrates into enantiomerically pure compounds.Numerous examples for their application in the preparation of synthetically useful chiral auxiliaries and building blocks for flavour compounds, pheromones and several pharmaceuticals including β-adrenergic blockers, antidepressants and ACE inhibitors are presented.
- Ader, U,Andersch, P,Berger, M,Goergens, U,Seemayer, R,Schneider, M
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p. 145 - 150
(2007/10/02)
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- Chiral Synthesis via Organoboranes. 18. Selective Reductions. 43. Diisopinocampheylchloroborane as an Excellent Chiral Reducing Reagent for the Synthesis of Halo Alcohols of High Enantiomeric Purity. A Highly Enantioselective Synthesis of Both Optical Isomers of Tomoxetine, Fluoxetine, a
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Diisopinocampheylchloroborane, dIpc2BCl, reduces ring and chain sustituted haloaralkyl ketones to the corresponding halo alcohols in excellent enantiomeric excess.In certain cases these alcohols can be upgraded by simple methods to essentially 100percent ee.For instance, (+)- or (-)-3-chloro-1-phenyl-1-propanol is initially obtained in 97percent ee.Simple recrystallisation then furnishes the pure enantiomers.These chiral halo alcohols are highly versatile intermediates.They can be readily cyclized to oxiranes and 2-substituted tetrahydrofurans with retention of chirality.Utilizing this methodology, we have developed an efficient, highly enantioselective synthesis of both optical isomers of the antidepressant drugs, Tomoxetine, Fluoxetine, and Nisoxetine, from the common intermediates (+)-or (-)-3-chloro-1-phenyl-1-propanol.
- Srebnik, Morris,Ramachandran, P.V.,Brown, Herbert C.
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p. 2916 - 2920
(2007/10/02)
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