- Biocatalytic asymmetric ring-opening of dihydroisoxazoles: a cyanide-free route to complementary enantiomers of β-hydroxy nitriles from olefins
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By combination of the cyanide-free synthesis of chiral nitriles and the Kemp elimination reaction catalyzed by aldoxime dehydratases, we herein report a new application of aldoxime dehydratase in the asymmetric ring-opening of 5-sub-4,5-dihydroisoxazoles
- Asano, Yasuhisa,Zheng, Daijun
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supporting information
p. 4930 - 4936
(2020/08/25)
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- Formation of carbanions from carboxylate ions bearing electron-withdrawing groups via photoinduced decarboxylation: Addition of generated carbanions to benzaldehyde
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The photoinduced decarboxylation of carboxylate ions bearing electron-withdrawing groups using biphenyl and 1,4-dicyanonaphthalene leads to the efficient generation of carbanions under mild conditions. The efficiency of the carbanion generation is strongl
- Kumagai, Yuta,Naoe, Takashi,Nishikawa, Keisuke,Osaka, Kazuyuki,Morita, Toshio,Yoshimi, Yasuharu
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p. 1668 - 1671
(2015/11/10)
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- Substrate evaluation of rhodococcus erythropolis SET1, a nitrile hydrolysing bacterium, demonstrating dual activity strongly dependent on nitrile sub-structure
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Assessment of Rhodococcus erythropolis SET1, a novel nitrile hydrolysing bacterial isolate, has been undertaken with 34 nitriles, 33 chiral and 1 prochiral. These substrates consist primarily of β-hydroxy nitriles with varying alkyl and aryl groups at the β position and containing in several compounds different substituents α to the nitrile. In the case of β-hydroxy nitriles without substitution at the α position, acids were the major products obtained, along with recovered nitrile after biotransformation, as a result of suspected nitrilase activity of the isolate. Unexpectedly, amides were found to be the major hydrolysis product when the β-hydroxy nitriles possessed a vinyl group at this position. To probe this behaviour further, additional related substrates were evaluated containing electron-withdrawing groups at the α position, and amide was also observed upon biotransformation in the presence of SET1. Therefore this novel isolate has also demonstrated NHase activity with nitriles that appears to be substrate-dependent.
- Coady, Tracey M.,Coffey, Lee V.,O'Reilly, Catherine,Lennon, Claire M.
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supporting information
p. 1108 - 1116
(2015/02/19)
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- A magnetic nanoparticle catalyzed eco-friendly synthesis of cyanohydrins in a deep eutectic solvent
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Magnetic Fe3O4 nanoparticles in deep eutectic solvents (DESs) have been regard as excellent catalysts for highly efficient cyanosilylation of various aldehydes and epoxides using trimethylsilyl cyanide TMSCN in high yields with excellent selectivity. Fe3O4 nanoparticles were synthesized and applied as a catalyst for the preparation of a wide variety of cyanohydrins (α-hydroxy nitriles and β-hydroxy nitriles) in readily available urea-choline chloride deep eutectic solvent DES as the most promising environmentally benign and cost-effective green solvent. Magnetic DES operates at very mild reaction conditions and can be easily recycled without significant loss of its catalytic activity.
- Azizi, Najmedin,Rahimi, Zahra,Alipour, Masoumeh
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p. 61191 - 61198
(2015/07/28)
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- Versatile iridicycle catalysts for highly efficient and chemoselective transfer hydrogenation of carbonyl compounds in water
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Cyclometalated iridium complexes are shown to be highly efficient and chemoselective catalysts for the transfer hydrogenation of a wide range of carbonyl groups with formic acid in water. Examples include α-substituted ketones (α-ether, α-halo, α-hydroxy, α-amino, α-nitrile or α-ester), α-keto esters, β-keto esters and α,β-unsaturated aldehydes. The reduction was carried out at substrate/catalyst ratios of up to 50000 at pH 4.5 and required no organic solvent. The protocol provides a practical, easy and efficient way for the synthesis of β-functionalised secondary alcohols, such as β-hydroxyethers, β-hydroxyamines and β-hydroxyhalo compounds, which are valuable intermediates in pharmaceutical, fine chemical, perfume and agrochemical synthesis. Water wonder: Iridicycle catalysts are versatile and allow the highly efficient and chemoselective transfer hydrogenation of a variety of carbonyl compounds, including problematic and challenging ones, with formate in neat water (see scheme).
- Talwar, Dinesh,Wu, Xiaofeng,Saidi, Ourida,Salguero, Noemí Poyatos,Xiao, Jianliang
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supporting information
p. 12835 - 12842
(2015/03/30)
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- N-Heterocyclic carbene-catalyzed cyanomethylation of aldehydes with TMSAN
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N-Heterocyclic carbenes (NHCs) have been served as efficient catalysts for cyanomethylation of carbonyl compounds. In the presence of 5 mol % NHC, various aldehydes and 2,2,2-trifluoroacetophenone reacted with trimethylsilylacetonitrile (TMSAN) to give β-hydroxynitriles in moderate to high yields.
- Fan, Ye-Cheng,Du, Guang-Fen,Sun, Wan-Fu,Kang, Wei,He, Lin
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supporting information; experimental part
p. 2231 - 2233
(2012/05/20)
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- One-pot nitrile aldolization/hydration operation giving β-hydroxy carboxamides
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Rhodium to the rescue: The formal aldol products of carboxamides (CONH 2) were obtained by using a RhI(OR) (R=H, Me) catalyst under essentially neutral pH and ambient conditions. This novel aldol strategy is based on the catalytic al
- Goto, Akihiro,Naka, Hiroshi,Noyori, Ryoji,Saito, Susumu
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supporting information; experimental part
p. 1740 - 1743
(2011/12/16)
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- P(i-PrNCH2CH2)3N as a Lewis base catalyst for the synthesis of β-hydroxynitriles using TMSAN
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(Equation Presented) Proazaphosphatrane 1a was found to be an efficient catalyst for synthesis of β-hydroxynitriles via the reaction of trimethylsilylacetonitrile (TMSAN) with aldehydes under mild reaction conditions and typically low catalyst loading (ca. 2 mol %). A variety of functional groups were tolerated, and good to excellent product yields were obtained.
- Wadhwa, Kuldeep,Verkade, John G.
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experimental part
p. 5683 - 5686
(2009/12/06)
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- Reaction of the electrogenerated cyanomethyl anion with carbonyl compounds: A clean and safe synthesis of β-hydroxynitriles
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The electrogenerated cyanomethyl anion reacts with carbonyl compounds to yield the corresponding β-hydroxymtriles in moderate to high yields. The reported methodology is very clean and safe, avoiding the use of any classical base or catalyst.
- Bianchi, Gabriele,Feroci, Marta,Rossi, Leucio
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experimental part
p. 3863 - 3866
(2010/01/11)
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- RhI-catalyzed aldol-type reaction of organonitriles under mild conditions
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An aldol-type reaction of organonitriles with aldehydes was catalyzed by a RhI(OR) species under ambient conditions, and the reaction displayed a broad substrate scope with respect to both organonitrile and aldehyde components. The Royal Societ
- Goto, Akihiro,Endo, Kohei,Ukai, Yu,Irle, Stephan,Saito, Susumu
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p. 2212 - 2214
(2008/12/22)
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- Catalytic nucleophilic activation of acetonitrile via a cooperative catalysis of cationic Ru complex, DBU, and NaPF6
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The development of an efficient catalytic system for the direct addition of acetonitrile under mild amine basic conditions is described. A cooperative catalysis of CpRu complex, DBU, and NaPF6 enables chemoselective and catalytic generation of
- Kumagai, Naoya,Matsunaga, Shigeki,Shibasaki, Masakatsu
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p. 8598 - 8608
(2008/02/10)
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- Unexpected stereorecognition in nitrilase-catalyzed hydrolysis of β-hydroxy nitriles
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Biocatalytic enantioselective hydrolysis of β-hydroxy nitriles to corresponding (S)-enriched β-hydroxy carboxylic acids has been achieved for the first time by an isolated nitrilase bII6402 from Bradyrhizobium japonicum USDA110. This offers a new "green" approach to optically pure β-hydroxy nitriles and β-hydroxy carboxylic acids. The observed remote stereorecognition is surprising because this nitrilase shows no enantioselectivity for the hydrolysis of α-hydroxy nitriles such as mandelonitrile.
- Kamila, Sukanta,Zhu, Dunming,Biehl, Edward R.,Hua, Ling
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p. 4429 - 4431
(2007/10/03)
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- Efficient nickel catalyst for coupling of acetonitrile with aldehydes
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A Ni complex of a diarylamido-based PNP ligand is an efficient and robust catalyst for coupling of acetonitrile with aldehydes. The Royal Society of Chemistry 2005.
- Fan, Lei,Ozerov, Oleg V.
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p. 4450 - 4452
(2007/10/03)
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- Cooperative catalysis of a cationic ruthenium complex, amine base, and Na salt: Catalytic activation of acetonitrile as a nucleophile
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Cooperative catalysis of a cationic Ru complex, DBU, and NaPF6 is described. An exquisite combination of the catalytic triad enabled catalytic activation of acetonitrile as a nucleophile under mild amine-basic conditions. Addition of in situ-ge
- Kumagai, Naoya,Matsunaga, Shigeki,Shibasaki, Masakatsu
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p. 13632 - 13633
(2007/10/03)
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- Chemoenzymatic synthesis2 of both enantiomers of fluoxetine, tomoxetine and nisoxetine: Lipase-catalyzed resolution of 3-aryl-3-hydroxypropanenitriles
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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.
- Kamal, Ahmed,Khanna,Ramu
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p. 2039 - 2051
(2007/10/03)
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- Tin-mediated organic reactions: A practical method for the synthesis of β-hydroxynitriles and β-hydroxyketones
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In the presence of chlorotrimethylsilane, the tin mediated addition of bromoacetonitrile or α-bromacetophenone to aldehydes in THF gives β- hydroxynitriles or β-hydroxyketones in moderate to good yields.
- Sun, Peipei,Shi, Baochuan
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p. 318 - 319
(2007/10/03)
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- PbCl2/Ga Bimetal Redox System-mediated Carbon-Carbon Bond Formation Reactions between Carbonyl Compounds and Ethyl Trichloroacetate and Iodonitrile
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In the presence of lead dichloride and a metallic gallium bimetal redox system, carbonyl compounds reacted with ethyl trichloroacetate and iodoacetonitrile to afford ethyl β-substituted α,α-dichloropropionates and β-hydroxy nitriles, respectively, in mode
- Zhang, Xiao-Lin,Han, Ying,Tao, Wen-Tian,Huang, Yao-Zeng
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p. 189 - 192
(2007/10/02)
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- AN ALDOL-TYPE REACTION OF ACETONITRILES USING DIALKYLBORYL TRIFLATE
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Acetonitriles and benzaldehydes react in the presence of dialkyl boryl triflate and diisopropylethylamine in dichloromethane to give the corresponding aldol-type products in good yields under mild conditions.
- Hamana, Hiroshi,Sugasawa, Tsutomu
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p. 1401 - 1404
(2007/10/02)
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