33537-18-7Relevant academic research and scientific papers
Biocatalytic Construction of Quaternary Centers by Aldol Addition of 3,3-Disubstituted 2-Oxoacid Derivatives to Aldehydes
Marín-Valls, Roser,Hernández, Karel,Bolte, Michael,Parella, Teodor,Joglar, Jesús,Bujons, Jordi,Clapés, Pere
supporting information, p. 19754 - 19762 (2020/12/01)
The congested nature of quaternary carbons hinders their preparation, most notably when stereocontrol is required. Here we report a biocatalytic method for the creation of quaternary carbon centers with broad substrate scope, leading to different compound classes bearing this structural feature. The key step comprises the aldol addition of 3,3-disubstituted 2-oxoacids to aldehydes catalyzed by metal dependent 3-methyl-2-oxobutanoate hydroxymethyltransferase from E. coli (KPHMT) and variants thereof. The 3,3,3-trisubstituted 2-oxoacids thus produced were converted into 2-oxolactones and 3-hydroxy acids and directly to ulosonic acid derivatives, all bearing gem-dialkyl, gem-cycloalkyl, and spirocyclic quaternary centers. In addition, some of these reactions use a single enantiomer from racemic nucleophiles to afford stereopure quaternary carbons. The notable substrate tolerance and stereocontrol of these enzymes are indicative of their potential for the synthesis of structurally intricate molecules.
SYNTHESIS METHOD FOR L-CYCLIC ALKYL AMINO ACID AND PHARMACEUTICAL COMPOSITION HAVING THEREOF
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Paragraph 0066-0067, (2016/11/17)
A synthesis method for L-cyclic alkyl amino acid and a pharmaceutical composition having the said amino acid are provide in the present disclosure provides. The synthesis method comprises: step A.) preparing a cyclic alkyl keto acid or a cyclic alkyl keto acid salt having Structural Formula (I) or Structural Formula (II), and step B.) mixing the cyclic alkyl keto acid or the cyclic alkyl keto acid salt with ammonium formate, a leucine dehydrogenase, a formate dehydrogenase and a coenzyme NAD+, and carrying out a reductive amination reaction to generate the L-cyclic alkyl amino acid, wherein the Structural Formula (I) is where n1≧1, m1≧0 and the M1 is H or a monovalent cation; the Structural Formula (II) is where n2≧0, m2≧0, the M2 is H or a monovalent cation, an amino acid sequence of the leucine dehydrogenase is SEQ ID No.1.
Catalytic cyclization reactions of Huisgen zwitterion with -ketoesters by in situ chemoselective phosphine oxide reduction
Fourmy, Kévin,Voituriez, Arnaud
supporting information, p. 1537 - 1540 (2015/03/30)
The first examples of catalytic cyclization reactions between the Huisgen zwitterion and α-ketoester derivatives are reported. The use of phenylsilane with a substoichiometric amount of bis(p-nitrophenyl)phosphate/diisopropylethylamine proved to be crucial for the in situ reduction of the phosphine oxide formed during the reaction. The optimized protocol is applied to alkyl or aryl ketoesters, furnishing either the corresponding cycloadducts or the hydrazone derivatives, depending on the substitution patterns of the substrates, in moderate to good yields (up to 80% yield, 18 examples).
Efficient synthesis of 2,6-disubstituted-5-hydroxy-3-oxo-2,3-dihydro-pyridazine-4-carboxylic acid ethyl esters
Murphy, Douglas E.,Dragovich, Peter S.,Ayida, Benjamin K.,Bertolini, Thomas M.,Li, Lian-Sheng,Ruebsam, Frank,Stankovic, Nebojsa S.,Sun, Zhongxiang,Zhao, Jingjing,Zhou, Yuefen
, p. 811 - 815 (2008/03/30)
A general procedure is described for the preparation of 6-substituted-5-hydroxy-3-oxo-2,3-dihydro-pyridazine-4-carboxylic acid ethyl esters (6-substituted-5-hydroxy-3(2H)-pyridazinone-4-carboxylic acid ethyl esters). These compounds are shown to undergo s
COMPOSITIONS FOR TREATING FLUSHING AND LIPID-ASSOCIATED DISORDERS COMPRISING NIACIN RECEPTOR PARTIAL AGONISTS
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Page/Page column 74, (2010/11/30)
The invention provides a method of reducing flushing induced by niacin or a niacin analog in a subject, comprising administering to said subject an effective flush reducing amount of a niacin receptor partial agonist. In addition, the invention provides a
1,2,4-TRIAZINES DERIVATIVES, PREPARATION THEREOF AND USE THEREOF IN HUMAN THERAPEUTICS
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Page/Page column 15-16, (2010/02/13)
The invention relates to 3,5-dioxo-(2H,4H)-1,2,4-triazine derivatives of general formulae (I or II), in which in particular: R1 represents hydrogen, a linear or branched C1-C6 alkyl or alkoxy radical, a C5-C6 cycloalkyl radical, a phenyl (C1-C2) alkyl radical or a phenyl radical;-R2 represents hydrogen, a linear or branched Cl-C7alkyl radical, or a C1-C6 alkyl radical substituted with groups such as trifluoromethyl or phenyl;- linker represents a C2-C6 alkyl chain or -(CH2)n-O- (n = 2 to 5), - R3 represents a group of general formula below for which X = O, linker can be connected to the ortho-, meta- or para-positions of the aromatic of the group R3, R4, R5, R6, R7 and R8 represent hydrogen or fluorine, R9, Rio and R11 represent hydrogen or a linear or branched Cl-C5 alkyl group, in particular R9 and Rio represent the methyl group and R11 represents hydrogen or the ethyl group.
Controlled release of perfumery aldehydes and ketones by Norrish type-II photofragmentation of α-keto esters in undegassed solution
Rochat, Sabine,Minardi, Caroline,De Saint Laumer, Jean-Yves,Herrmann, Andreas
, p. 1645 - 1671 (2007/10/03)
Alkyl or aryl α-keto esters of primary or secondary alcohols decompose upon irradiation at 350-370 nm from the intermediate triplet state into aldehydes or ketones in polar, as well as apolar solvents. The use of these keto esters as delivery systems for the controlled release of perfumery aldehydes and ketones was investigated by photoirradiation in the presence of oxygen with a Xe or UV lamp, as well as outdoor sunlight. Systematic GC/MS analysis of the irradiated solutions showed that, under these conditions, the desired Norrish type-II fragmentation of the ester side chain is the predominant reaction pathway in most of the cases. γ-H Abstraction from the alkyl side chain of alkyl keto esters, as well as an intramolecular Paterno- Buchi reaction or epoxidation of the alkene function in different citronellyl α-keto esters were identified as the most important side reactions. Some of the experimental findings have been rationalized on the basis of ab initio and density-functional calculations. (Cyclohexyl)oxoacetates and oxo(phenyl)acetates were found to be the most suitable precursors for the desired perfumery applications.
Studies on Conjugated Nitriles. IV. Reaction of Ethyl Cyanoformate with Organomagnesium, -zinc, and - cadmium Reagents, and Phosphonium Ylide
Akiyama, Yasunobu,Takebayashi, Shoko,Kawasaki, Tomomi,Sakamoto, Masanori
, p. 1800 - 1807 (2007/10/02)
The reaction of ethyl cyanoformate (1a) with phenylcadmium bromide (3a) gave ethyl benzoate (4), ethyl 2-phenyl-2-oxoacetate (5a), and 2-ethoxycarbonyl-2,4-diphenyl-3-imidazoline-5-one (6).In the presence of zinc chloride, the addition of 3a to the cyano group of 1a occured to give only 5a.The similar reaction of 1a with other organocadmium reagents (3b-f) in the presence of zinc chloride gave the corresponding α-ketoesters (5b-f) in moderate yields.The reactions of 1a with other organometallic reagents, e.g. phenylmagnesium (2a), -zinc (8) and -mercuric bromide (9) in the presence or in the absence of zinc chloride were examined.Furthermore, the addition of phosphonium ylide 13a to the cyano group of 1a in the presence of stannic chloride occured exclusively to give the phosphonium salt 14.The results are discussed in terms of the hard and soft acids and bases (HSAB) principle.Keywords - ethyl cyanoformate; benzoyl cyanide; organocadmium reagent; organozinc reagent; phosphonium ylide; cyano group addition; α-ketoester; α-dehydroamino ester; Lewis acid
