191720-36-2

Upstream product

• 455-19-6 4-Trifluoromethylbenzaldehyde 
• 74-90-8 hydrogen cyanide 
• 7677-24-9 trimethylsilyl cyanide 
• 151-50-8 potassium cyanide 
• 75-86-5 2-hydroxy-2-methylpropanenitrile 
• 108-05-4 vinyl acetate 
• 168013-75-0 (+/-)-2-hydroxy-2-(4-trifluoromethylphenyl)acetonitrile 
• 124862-65-3 α-acetoxy-4-(trifluoromethyl)benzeneacetonitrile 
• 73183-23-0 2-(4-(trifluoromethyl)phenyl)-2-((trimethylsilyl)oxy)acetonitrile 

Downstream Products

• 196302-06-4 (S)-4-(trifluoromethyl)mandelic acid 

Relevant academic research and scientific papers

An orthogonal biocatalytic approach for the safe generation and use of HCN in a multistep continuous preparation of chiral O-acetylcyanohydrins

An enantioselective preparation of O-acetylcyanohydrins has been accomplished by a three-step telescoped continuous process. The modular components enabled an accurate control of two sequential biotransformations, safe handling of an in situ generated hazardous gas, and in-line stabilization of products. This method proved to be advantageous over the batch protocols in terms of reaction time (40 min vs 345 min) and ease of operation, opening up access to reactions which have often been neglected due to safety concerns.

Enantioselective cyanosilylation of aldehydes catalyzed by a multistereogenic salen-Mn(III) complex with a rotatable benzylic group as a helping hand

A multistereogenic salen-Mn(iii) complex bearing an aromatic pocket and two benzylic groups as helping hands was found to be efficient in the catalysis of asymmetric cyanosilylation. The salen-Mn catalyst partially mimics the functions of biocatalysts by

Investigation of lewis acid versus lewis base catalysis in asymmetric cyanohydrin synthesis

The asymmetric addition of trimethylsilyl cyanide to aldehydes can be catalysed by Lewis acids and/or Lewis bases, which activate the aldehyde and trimethylsilyl cyanide, respectively. It is not always apparent from the structure of the catalyst whether Lewis acid or Lewis base catalysis predominates. To investigate this in the context of using salen complexes of titanium, vanadium and aluminium as catalysts, a Hammett analysis of asymmetric cyanohydrin synthesis was undertaken. When Lewis acid catalysis is dominant, a significantly positive reaction constant is observed, whereas reactions dominated by Lewis base catalysis give much smaller reaction constants. [{Ti(salen)O}2] was found to show the highest degree of Lewis acid catalysis, whereas two [VO(salen)X] (X = EtOSO3 or NCS) complexes both displayed lower degrees of Lewis acid catalysis. In the case of reactions catalysed by [{Al(salen)}2O] and triphenyl- phosphine oxide, a non-linear Ham- mett plot was observed, which is indicative of a change in mechanism with increasing Lewis base catalysis as the carbonyl compound becomes more electron-deficient. These results suggested that the aluminium complex/tri- phenylphosphine oxide catalyst system should also catalyse the asymmetric addition of trimethylsilyl cyanide to ke- tones and this was found to be the case.

Enzymatic kinetic resolution of racemic cyanohydrins via enantioselective acylation

Enzymatic kinetic resolution of a series of aromatic and aliphatic cyanohydrins in organic media has been investigated. The behavior of potential lipases, molecular sieves, acyl reagent, reaction temperature, and organic solvents on the kinetic resolution was studied. The influence of substrate structure, steric, and electronic nature and position of the aryl substituent on the enantioselectivity was discussed. Under the optimized reaction conditions, good enantioselectivity could be achieved for most of the investigated compounds. Specifically, substrates 1a, 1c, 1d, 1f, 1u could be resolved with the kinetic enantiomer ratio (E) higher than 200.

Lipase-catalyzed dynamic kinetic resolution giving optically active cyanohydrins: use of silica-supported ammonium hydroxide and porous ceramic-immobilized lipase

Synthetically useful cyanohydrin acetates, ArCH(OAc)CN (Ar=C6H5, 3,4-methylenedioxyphenyl, 4-Me-C6H4, 4-Cl-C6H4, 4-F-C6H4, 4-CF3-C6H4), were successfully synthesized in high enantiomeric purities (79-93% ee) via the lipase-catalyzed dynamic kinetic resolution (DKR) of cyanohydrins synthesized in situ from the corresponding aldehydes and acetone cyanohydrin. The combined use of silica-supported BTAH (benzyltrimethylammonium hydroxide) and porous ceramic-immobilized lipase under the optimized reaction conditions enabled the remarkable acceleration of the enantioselective DKR reactions.

A new (R)-hydroxynitrile lyase from Prunus mume: Asymmetric synthesis of cyanohydrins

A new hydroxynitrile lyase (HNL) was isolated from the seed of Japanese apricot (Prunus mume). The enzyme has similar properties with HNL isolated from other Prunus species and is FAD containing enzyme. It accepts a large number of unnatural substrates (benzaldehyde and its variant) for the addition of HCN to produce the corresponding cyanohydrins in excellent optical and chemical yields. A new HPLC based enantioselective assay technique was developed for the enzyme, which promotes the addition of KCN to benzaldehyde in a buffered solution (pH=4.5).

METHOD FOR PRODUCING SUBSTITUTED SHIRAL DIOLS AND DIOL-ANALOGOUS DERIVATIVES

The invention relates to a method for producing substituted shiral diols and the derivatives thereof of formula (I), wherein R is H or possibly substituted C5-C20-aryl-, C5-C20-heterocycle or C1-C20 alkyl radical or R1is possibly substituted C5-C20-aryl, C5-C20-heterocycle or C1-C20 alkyl; R2 is H or C1-C20 alkyl, C3-C7-heterocycle, silyl, C5-C20-aryl, C5-C20-arylsulphonyl or C1-C20-alkylsulphonyl; R3 is H or an O protection group; and X is oxygen, sulphur, nitrogen or phosphorus. The inventive method consists a) in transforming hydroxycarboxylic acid of formula (II), wherein R4 id H or C1-C6 alkyl provided with a link of the O protection group into a component of formula (III), wherein R3 is the O protection group; b) in reducing said acid into a compound of formula (IV) with alkali boron-or aluminium hydride; c) possibly activating and exchanging one oxygen atom against a radical containing one sulphur, nitrogen or phosphorus atom; or d) possibly transforming said acid with alkylation or arylation reagents into a compound of formula (V), wherein R′2 is possibly substituted C1-C20 alkyl-, C3-C7-heterocyclic-, silyl-, C5-C20-aryl-, C5-C20-arylsulphonyl or C1-C20- alkylsulphonyl and R3 is O protection group,

BMPD, a novel C2-chiral 1,3-diketone ligand; synthesis and application to an asymmetric catalytic reaction

The synthesis of BMPD, 1,3-bis(2-methylferrocenyl)-propane-1,3-dione, was achieved via the Claisen condensation of a homochiral ferrocenecarboxylate and an acetylferrocene derived from the same chiral formylferrocene. Several metal complexes were prepared to exemplify the complexation ability of BMPD. A BMPD-yttrium complex was found to act as a new catalyst for silylcyanation of aldehydes with remarkable efficiency. As little as 0.2 mol% of the complex catalyzed the reaction of benzaldehyde and cyanotrimethylsilane to afford the cyanohydrin in 95% yield with 87% ee.

Asymmetric Hydrocyanation of a Range of Aromatic and Aliphatic Aldehydes

A range of aryl, alkyl and heterocyclic aldehydes have been treated with hydrogen cyanide in the presence of the 'Inoue' catalyst, (R,R)- or (S,S)-cyclo.Most aryl aldehydes with electron-donating substituents in the m-or p-positions give high enantiomeric excess (e.e) values (>=80percent) but aryl aldehydes with strong electron-withdrawing substituents gave moderate e.e. values (=50percent).These moderate values are believed to be due to partial racemization of the product cyanohydrins in the presence of the mildly basic catalyst.In contrast to the reactions of aryl aldehydes, reactions of alkyl aldehydes and of ketones gave low e.e. values (=30percent) and an explanation is proposed.