15344-34-0Relevant academic research and scientific papers
Studies on phosphoroheterocycle chemistry III: An unusual way to 1,3,2-thiazaphospholidine-4-thione 2-sulfide derivatives
Deng, ShengLou,Chen, RuYu
, p. 2527 - 2531 (2002)
An unusual but efficient method for the synthesis of phosphoroheterocycles, 1,3,2-thiazaphospholidine-4-thione 2-sulfide derivatives, by the reaction of Lawesson's reagent with a variety of α-hydroxy nitriles has been developed. The possible mechanism of the reaction is proposed to involve thiation of hydroxy group in a first step, sequential addition of P-SH to the nitrile and rearrangement resulting in the title phosphoroheterocycles. The preliminary bioassays show that these heterocyclic compounds have herbicidal properties.
Direct C(sp3)-H Cyanation Enabled by a Highly Active Decatungstate Photocatalyst
Kim, Kunsoon,Lee, Seulchan,Hong, Soon Hyeok
supporting information, p. 5501 - 5505 (2021/07/26)
A highly efficient, direct C(sp3)-H cyanation was developed under mild photocatalytic conditions. The method enabled the direct cyanation of various C(sp3)-H substrates with excellent functional group tolerance. Notably, complex natural products and bioactive compounds were efficiently cyanated.
Enantioselective Synthesis of α-Thiocarboxylic Acids by Nitrilase Biocatalysed Dynamic Kinetic Resolution of α-Thionitriles
Lauder, Kate,Anselmi, Silvia,Finnigan, James D.,Qi, Yuyin,Charnock, Simon J.,Castagnolo, Daniele
supporting information, p. 10422 - 10426 (2020/07/24)
The enantioselective synthesis of α-thiocarboxylic acids by biocatalytic dynamic kinetic resolution (DKR) of nitrile precursors exploiting nitrilase enzymes is described. A panel of 35 nitrilase biocatalysts were screened and enzymes Nit27 and Nit34 were found to catalyse the DKR of racemic α-thionitriles under mild conditions, affording the corresponding carboxylic acids with high conversions and good-to-excellent ee. The ammonia produced in situ during the biocatalytic transformation favours the racemization of the nitrile enantiomers and, in turn, the DKR without the need of any external additive base.
A 2 - hydroxy dissidents calcium synthetic method
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Paragraph 0020-0022; 0030-0032; 0039-0041, (2019/07/05)
The invention discloses a 2 - hydroxy dissidents calcium synthetic method: to different pentanals, sodium bisulfite, sodium cyanide as raw material through nucleophilic addition reaction in the synthesis of 2 - hydroxy different fifth heavenly stem nitrile, then in acidic conditions by the hydrolysis reaction of the 2 - hydroxy dissidents acid, the final calcium salt exchange reaction 2 - hydroxy dissidents calcium, then refined to get the pure product 2 - hydroxy dissidents acid calcium, refined pure product purity as high as 99.7%, three-step [...] yield is up to 80% or more. The method has the production cycle is short, simple and convenient operation, is suitable for industrial production.
Catalytic asymmetric synthesis of secondary nitriles via stereoconvergent negishi arylations and alkenylations of racemic α-bromonitriles
Choi, Junwon,Fu, Gregory C.
supporting information; experimental part, p. 9102 - 9105 (2012/07/13)
The first method for the stereoconvergent cross-coupling of racemic α-halonitriles is described, specifically, nickel-catalyzed Negishi arylations and alkenylations that furnish an array of enantioenriched α-arylnitriles and allylic nitriles, respectively. Noteworthy features of this investigation include: the highly enantioselective synthesis of α-alkyl-α-aryl nitriles that bear secondary α-alkyl substituents; the first examples of the use of alkenylzinc reagents in stereoconvergent Negishi reactions of alkyl electrophiles; demonstration of the utility of a new family of ligands for asymmetric Negishi cross-couplings (a bidentate bis(oxazoline), rather than a tridentate pybox); in the case of arylzinc reagents, carbon-carbon bond formation at a remarkably low temperature (-78 °C), the lowest reported to date for an enantioselective cross-coupling of an alkyl electrophile; a mechanistic dichotomy between Negishi reactions of an unactivated versus an activated secondary alkyl bromide.
Unsymmetric salen ligands bearing a Lewis base: Intramolecularly cooperative catalysis for cyanosilylation of aldehydes
Wen, Ye-Qian,Ren, Wei-Min,Lu, Xiao-Bing
supporting information; experimental part, p. 6323 - 6330 (2011/10/09)
A series of unsymmetric salen ligands derived from 1,2-diaminocyclohexane bearing an appended Lewis base on the three-position of one aromatic ring were synthesized by the reaction of various functional salicyaldehydes with the condensation product of 1,2-diaminocyclohexane mono(hydrogen chloride) and 3,5-di-tert-butylsalicylaldehyde. These ligands in conjunction with Ti(O iPr)4 exhibited excellent activity in catalyzing the cyanosilylation of aldehydes with trimethylsilyl cyanide (TMSCN) at mild conditions. The highest activity was observed in the catalyst system with regard to the salen ligand bearing a diethylamino group, which proved to be active even at a high [aldehyde]/[catalyst] ratio up to 50000. In a low catalyst loading of 0.05 mol%, the quantitative conversion of benzaldehyde to the corresponding cyanosilylation product was found within 10 min. at ambient temperature. An intramolecularly cooperative catalysis was proposed wherein the central metal Ti(iv) is suggested to play a role of Lewis acid to activate aldehydes while the appended Lewis base to activate TMSCN.
Pyrazolotriazines
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Page/Page column 45, (2009/07/10)
Compounds of a certain formula I, in which R1, R2, A, R4, B, R5 and R6 have the meanings indicated in the description, are effective compounds with anti-proliferative and/or apoptosis inducing activity.
Synthesis of aliphatic (S)-α-hydroxycarboxylic amides using a one-pot bienzymatic cascade of immobilised oxynitrilase and nitrile hydratase
Van Pelt, Sander,Van Rantwijk, Fred,Sheldon, Roger A.
experimental part, p. 397 - 404 (2009/12/01)
A one-pot bienzymatic cascade combining a hydroxynitrile lyase (Manihot esculenta, E.C. 4.1.2.10) and a nitrile hydratase (Nitriliruptor alkaliphilus, E.C. 4.2.1.84) for the synthesis of enantiopure aliphatic α- hydroxycarboxylic amides from aldehydes is described. Both enzymes were immobilised as cross-linked enzyme aggregates (CLEAs). Stability tests show that the nitrile hydratase CLEAs are sensitive to water-immiscible organic solvents as well as to aldehydes and hydrogen cyanide (HCN), but are remarkably stable and show useful activity in acidic aqueous environments of pH 4-5. The cascade reactions are consequently carried out by using a portionwise feed of HCN and moderate concentrations of aldehyde in acidic aqueous buffer to suppress the uncatalysed hydrocyanation background reaction. After optimisation, this method was used to synthesise five different kinds of aliphatic α- hydroxycarboxylic amides from the corresponding aldehydes with good yields and with enantiomeric purities comparable to those obtained for the α-hydroxynitriles in the microaqueous hydrocyanation using hydroxynitrile lyase and an excess of HCN.
Stereospecific α-methallylation of hydroxyaldehydes by silatropic ene cyclisation
Robertson, Jeremy,Hall, Michael J.,Green, Stuart P.
experimental part, p. 5541 - 5551 (2009/12/09)
We describe the thermal rearrangement of aldehydes bearing an α-(allyl- or crotylsilyl)oxy substituent. The transformations are best described mechanistically as intramolecular silatropic ene reactions based on stereoselectivity, kinetic and computed transition state data. The overall process constitutes a stereospecific (meth)allylation of α-hydroxyaldehydes, under neutral conditions, in which the hydroxyl protecting group is also the (meth)allylating agent.
Purification and characterization of a novel (R)-hydroxynitrile lyase from Eriobotrya japonica (Loquat)
Ueatrongchit, Techawaree,Kayo, Ai,Komeda, Hidenobu,Asano, Yasuhisa,H-Kittikun, Aran
, p. 1513 - 1522 (2008/12/21)
A hydroxynitrile lyase was isolated and purified to homogeneity from seeds of Eriobotrya japonica (loquat). The final yield, of 36% with 49-fold purification, was obtained by 30-80% (NH4)2SO4 fractionation and column chromatography on DEAE-Toyopearl and Concanavalin A Sepharose 4B, which suggested the presence of a carbohydrate side chain. The purified enzyme was a monomer with a molecular mass of 72 kDa as determined by gel filtration, and 62.3 kDa as determined by SDS-gel electrophoresis. The N-terminal sequence is reported. The enzyme was a flavoprotein containing FAD as a prosthetic group, and it exhibited a Km of 161 μM and a k cat/Km of 348 s-1 mM-1 for mandelonitrile. The optimum pH and temperature were pH 5.5 and 40°C respectively. The enzyme showed excellent stability with regard to pH and temperature. Metal ions were not required for its activity, while activity was significantly inhibited by CuSO4, HgCl2, AgNO3, FeCl3, β-mercaptoethanol, iodoacetic acid, phenylmethylsulfonylfluoride, and diethylpyrocarbonate. The specificity constant (kcat/Km) of the enzyme was investigated for the first time using various aldehydes as substrates. The enzyme was active toward aromatic and aliphatic aldehydes, and showed a preference for smaller substrates over bulky one.
