- The Synthesis of Chiral α-Aryl α-Hydroxy Carboxylic Acids via RuPHOX-Ru Catalyzed Asymmetric Hydrogenation
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A ruthenocenyl phosphino-oxazoline-ruthenium complex (RuPHOX?Ru) catalyzed asymmetric hydrogenation of α-aryl keto acids has been successfully developed, affording the corresponding chiral α-aryl α-hydroxy carboxylic acids in high yields and with up to 97% ee. The reaction could be performed on a gram scale with a relatively low catalyst loading (up to 5000 S/C) and the resulting products can be transformed to several chiral building blocks, biologically active compounds and chiral drugs. (Figure presented.).
- Guo, Huan,Li, Jing,Liu, Delong,Zhang, Wanbin
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p. 3665 - 3673
(2017/09/11)
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- Chemoenzymatic Preparation of Enantiomerically Enriched (R)-(–)-Mandelic Acid Derivatives: Application in the Synthesis of the Active Agent Pemoline
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The enantioselective resolution of several racemic derivatives of mandelic acid methyl ester catalyzed by lipases from Pseudomonas fluorescens (Amano AK) or Burkholderia cepacia (Amano PS-C II and Amano PS-IM) has been achieved. A gram-scale lipase-mediated kinetic resolution approach has been developed that allows the facile synthesis of the corresponding methyl (R)-(–)-mandelates with excellent enantiomeric excesses (up to >99 % ee) and reaction enantioselectivity (E values up to >200). The dopaminergic agent pemoline, used in the treatment of attention-deficit hyperactivity disorder (ADHD) and narcolepsy, was synthesized with 98 % ee in a straightforward route by condensing the prepared methyl (R)-(–)-mandelate with guanidine hydrochloride under basic conditions. The desired (R)-(+)-pemoline in optically pure form (>99 % ee) was obtained after two recrystallizations from ethanol. However, it was confirmed by chiral HPLC that optically active pemoline undergoes racemization in methanol solution.
- Potera?a, Marcin,Dranka, Maciej,Borowiecki, Pawe?
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p. 2290 - 2304
(2017/05/01)
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- CANNABINOID RECEPTOR MODULATOR
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A cannabinoid receptor modulator containing a compound represented by Formula (I0) wherein, X is an oxygen atom, etc., R° is an optionally substituted acylamino group, ring A0 is a benzene ring which may further have a substituent in addition to R°, and ring B is an optionally substituted 5-membered heterocycle, or a salt thereof or a prodrug thereof.
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Page/Page column 47
(2008/06/13)
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- Amides for the treatment of atherosclerosis
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This invention provides amide compounds as inhibitors of acyl-Coenzyme A: cholesterol O-acyltransferase (ACAT), pharmaceutical compositions containing such compounds, processes for the preparation of such compounds, and the use of such compounds as antihypercholesterolemic and/or antiatherosclerotic agents.
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