82782-11-4Relevant academic research and scientific papers
Chemoenzymatic synthesis2 of both enantiomers of fluoxetine, tomoxetine and nisoxetine: Lipase-catalyzed resolution of 3-aryl-3-hydroxypropanenitriles
Kamal, Ahmed,Khanna,Ramu
, p. 2039 - 2051 (2007/10/03)
A facile preparation of (±)-3-hydroxy-3-phenylpropanenitrile has been carried out by ring-opening of styrene oxide with NaCN in aqueous ethanol. Subsequent kinetic resolution of this material via lipase-mediated transesterification gave the S-alcohol and R-acetate in excellent yields and high enantioselectivities, particularly with lipase PS-C 'Amano' II. The effect of solvents and immobilization of the lipase has also been investigated. It is interesting to note that the use of immobilized lipase for this transesterification process in hydrophobic solvents (diisopropyl ether, toluene and hexane) enhanced the reaction rate drastically and gave optimal yields with high enantioselectivity (>99%). Moreover, enantiopure 3-hydroxy-3-phenylpropanenitrile products have been converted via enantioconvergent routes into the (R)- and (S)-enantiomers of the important anti-depressants fluoxetine, tomoxetine, nisoxetine and norfluoxetine.
Thiacrown Ether Technology in Lipase-Catalyzed Reaction: Scope and Limitation for Preparing Optically Active 3-Hydroxyalkanenitriles and Application to Insect Pheromone Synthesis
Itoh, Toshiyuki,Mitsukura, Koichi,Kanphai, Wipa,Takagi, Yumiko,Kihara, Hiroshi,Tsukube, Hiroshi
, p. 9165 - 9172 (2007/10/03)
Both reaction rate and enantioselectivity in Pseudomonas cepacia lipase (PCL)-catalyzed hydrolysis of 3-hydroxyalkanenitrile acetates were significantly changed by the addition of catalytic amounts of thiacrown ether (1,4,8,11-tetrathiacyclotetradecane). Although the reaction rate of various nitriles was accelerated, the enantioselectivity greatly depended on the nature of the substrate. Among 10 substrates tested, thiacrown ether offered highest enantioselectivity in PCL-catalyzed hydrolysis of 1-(cyanomehtyl)propyl acetate. Forty or more times this crown ether, molarity based on the enzyme, was required to attain an acceptably high reaction rate and enantioselectivity. Applying this technology, we succeeded in synthesizing the optically pure attractant pheromone of ant Myrmica scabrinodis (A), (R)-3-octanol and its antipode of (S)-isomer in good overall yields.
Zinc-Promoted Reactions. 9. The Fate of the Cyano Group in the Reduction of Simple Cyanoketones and N-Cyanoamines
Vona, Maria Luisa Di,Luchetti, Luciana,Rosnati, Vittorio
, p. 8203 - 8208 (2007/10/02)
The Zn/AcOH reduction of 1 leads only to the carbonyl reduction, while C-decyanation occurs in the case of 2.The mechanism of the latter reaction is discussed.The N-decyanation of N-cyanoamines 3 and 4 involves an ionic mechanism, leading to N-acyl derivatives and isocyanic acid, the latter compound being ultimately reduced to formic acid.
Silyl Nitronates in Organic Synthesis. Routes to Heterocycles and Cyclopentanoids. Synthesis of Allethrolone and Calythrone. Acylation and Cyanohydroxylation of Double Bonds. An Exploratory Study
Andersen, Soeren H.,Das, Nalin B.,Joergensen, Ruth D.,Kjeldsen, Gunhild,Knudsen, Jes S.,et al.
, p. 1 - 14 (2007/10/02)
Silyl nitronates are versatile reagents for the preparation of heterocycles by dipolar addition to double bonds.The intermediate isoxazolidines can be transformed to 2-isoxazolines, isoxazoles, furans, dihydrofuranones, pyrazoles, pyridazines and pyridazones.Reduction of 2-isoxazolines with Ti3+ leads to hydroxylated 1,4-diketones, which subsequently can be cyclized to cyclopentenones.Routes to calythrone, rethrolones, prostanoids and a number of naturally occurring dihydrofuranones are devised, as well as synthetic procedures for acylation, preparation of endiones, hydroxyacylation, cyanation and hydroxycyanation of double bonds.
