76062-97-0Relevant articles and documents
A FACILE METHOD FOR PREPERATION OF THE OPTICALLY PURE 3-HYDROXYTETRADECANOIC ACID BY AN APPLICATION OF ASYMMETRICALLY MODIFIED NICKEL CATALYST
Tai, Akira,Nakahata, Masaaki,Harada, Tadao,Izumi, Yoshiharu,Kusumoto, Shoichi,et al.
, p. 1125 - 1126 (1980)
The enantioface-differentiating hydrogenation of methyl 3-oxotetradecanoate(R,R)-tartaric acid-NaBr-modified nickel gave methyl (R)-3-hydroxytetradecanoate(III) in 85percent e.e..After III was converted to dicyclohexylammonium salt of 3-hydroxytetradecanoic acid (I), the salt was recrystallized three times from acetonitrile and was then treated with acid to give optically pure (R)-I in a good yield.
A Unique Combination of Two Different Quorum Sensing Systems in the β-Rhizobium Cupriavidus taiwanensis
Wakimoto, Takayuki,Nakagishi, Shiori,Matsukawa, Nao,Tani, Shuji,Kai, Kenji
, p. 1876 - 1884 (2020)
Cupriavidus taiwanensis LMG19424, a β-rhizobial symbiont of Mimosa pudica, harbors phc and tqs quorum sensing (QS), which are the homologous cell-cell communication systems previously identified from the plant pathogen Ralstonia solanacearum and the human pathogen Vibrio cholerae, respectively. However, there has been no experimental evidence reported that these QS systems function in C. taiwanensis LMG19424. We identified (R)-methyl 3-hydroxymyristate (3-OH MAME) and (S)-3-hydroxypentadecan-4-one (C15-AHK) as phc and tqs QS signals, respectively, and characterized these QS systems. The expression of the signal synthase gene phcB and tqsA in E. coli BL21(DE3) resulted in the high production of 3-OH MAME and C15-AHK, respectively. Their structures were elucidated by comparison of EI-MS data and GC/chiral LC retention times with synthetic standards. The deletion of phcB reduced cell motility and increased biofilm formation, and the double deletion of phcB/tqsA caused the accumulation of the metal chelator coproporphyrin III in its mutant culture. Although the deletion of phcB and tqsA slightly reduced its ability to nodulate on aseptically grown seedlings of M. pudica, there was no significant difference in nodule formation between LMG19424 and its QS mutants when commercial soils were used. Taken together, this is the first example of the simultaneous production of 3-OH MAME/C15-AHK as QS signals in a bacterial species, and the importance of the phc/tqs QS systems in the saprophytic stage of C. taiwanensis LMG19424 is suggested.
Chiral Surfactant-Type Catalyst: Enantioselective Reduction of Long-Chain Aliphatic Ketoesters in Water
Lin, Zechao,Li, Jiahong,Huang, Qingfei,Huang, Qiuya,Wang, Qiwei,Tang, Lei,Gong, Deying,Yang, Jun,Zhu, Jin,Deng, Jingen
, p. 4419 - 4429 (2015/05/13)
A series of amphiphilic ligands were designed and synthesized. The rhodium complexes with the ligands were applied to the asymmetric transfer hydrogenation of broad range of long-chained aliphatic ketoesters in neat water. Quantitative conversion and excellent enantioselectivity (up to 99% ee) was observed for α-, β-, γ-, δ- and ε-ketoesters as well as for α- and β-acyloxyketone using chiral surfactant-type catalyst 2. The CH/π interaction and the strong hydrophobic interaction of long aliphatic chains between the catalyst and the substrate in the metallomicelle core played a key role in the catalytic transition state. Synergistic effects between the metal-catalyzed site and the hydrophobic microenvironment of the core in the micelle contributed to high stereoselectivity. (Chemical Equation Presented).
Asymmetric synthesis of long chain β-hydroxy fatty acid methyl esters as new elastase inhibitors
Hasdemir, Belma,Onar, Huelya Elik,Yusufolu, Aye
, p. 1100 - 1105 (2012/11/07)
Herein, β-hydroxy methyl esters with an even carbon chain length of 12-20 1b-5b were synthesized by three different asymmetric reduction methods I, II III from their corresponding β-keto methyl esters 1a-5a with the aim of determining their elastase activities. In method I, chiral catalyst A was prepared from chiral ligand (R)-binaphthol 1, while in method II, chiral catalyst B was synthesized from (2R,3R)-diisopropyl tartrate 2. Chiral catalyst B has not previously been used in asymmetric borane reductions or in the asymmetric synthesis of chiral β-hydroxy methyl esters. In method III, an asymmetric reduction was catalysed by (R)-Me-CBS oxazaborolidine 3. Hydride transfer was carried out in all of these methods by BH3· SMe2. Chiral hydroxy methyl esters with an (S)-configuration were synthesized by method I and with an (R)-configuration via methods II and III. The chiral hydroxy methyl esters obtained were analysed by chiral HPLC for their ee % values. Methods I, II and III were applied to long chain β-keto methyl esters for the first time. The reduction methods I, II and III were examined in terms of reaction yield and enantiomeric excess according to carbon chain length and the variable ratio of chiral catalysts to β-keto methyl ester. The highest enantiomeric excess of 90% ee was found in method III for 12 and 14 carbon numbers.
Enantioselective synthesis of α-amino acids from N-tosyloxy β-lactams derived from β-keto esters
Durham, Timothy B.,Miller, Marvin J.
, p. 27 - 34 (2007/10/03)
A novel synthetic sequence has been developed to convert simple β-keto esters into enantiomerically enriched α-amino acids. The key features of this sequence include the addition of azide to the C3 position of β-keto ester derived N-tosyloxy-β-lactams through a concomitant nucleophilic addition/N-O bond reduction reaction, a mild CsF-induced N1 benzylation of α-azido monocyclic β-lactams, the preparation of α-keto-β-lactams through a novel four-step sequence from the corresponding 3-azido-1-benzyl-β-lactams, and TEMPO-mediated ring expansion of these compounds to the corresponding N-carboxy anhydrides (NCAs). In addition, the synthesis, isolation, and characterization of unusual 3-imino and 3-chloramino-β-lactams is reported.
Enzymatic preparation of (S)-3-hydroxytetradecanoic acid and synthesis of unnatural analogues of lipid A containing the (S)-acid
Liu, Wen-Chi,Oikawa, Masato,Fukase, Koichi,Suda, Yasuo,Winarno, Hendig,Mori, Saeko,Hashimoto, Masahito,Kusumoto, Shoichi
, p. 1441 - 1450 (2007/10/03)
Synthesis of unnatural analogues, that contain (S)-3-hydroxytetradecanoyl moieties in place of the corresponding natural (R)-isomers, of both lipid A and its biosynthetic precursor, designated precursor Ia or lipid IV(A), has been achieved through our recently developed procedure. (S)-3-Hydroxytetradecanoic acid was prepared from its racemate through the optical resolution by the use of a lipase and subsequent fractional recrystallization. The (S)-acyl analogue of lipid A exhibited slightly stronger interleukin-6 inducing activity than the corresponding natural lipid A, and the (S)-acyl analogue of the biosynthetic precursor was far more active than the natural precursor in inhibiting the induction of interleukin-6 by lipopolysaccharide.
Synthesis of an analog of biosynthetic precursor la of lipid A by an improved method: A novel antagonist containing four (S)-3-hydroxy fatty acids
Fukase, Koichi,Liu, Wen-Chi,Suda, Yasuo,Oikawa, Masato,Wada, Akira,Mori, Saeko,Ulmer, Arthur J.,Rietschel, Ernst Th.,Kusumoto, Shoichi
, p. 7455 - 7458 (2007/10/02)
Synthesis of an analog of a biosynthetic precursor of lipid A containing four (S)-3-hydroxytetradecanoic acids was effected via an improved synthetic route to investigate the relationship between the bioactivity and the chirality of the 3-hydroxy fatty acid residues in lipid A. The S-analog inhibited endotoxin-induced interleukin-6 (IL-6) production from human peripheral whole blood cells more strongly than the natural-type biosynthetic precursor with (R)-hydroxy acids, a known antagonist of LPS-induced cytokine release in human peripheral blood mononuclear cells.
An Improved Asymmetrically-Modified Nickel Catalyst Prepared from Ultrasonicated Raney Nickel
Tai, Akira,Kikukawa, Tadashi,Sugimura, Takashi,Inoue, Yoshihisa,Abe, Satoshi,et al.
, p. 2473 - 2477 (2007/10/02)
The ultrasonic irradiation of Raney nickel catalyst in water followed by the removal of the resulting turbid supernatant gave an excellent nickel catalyst (RNi-U) which generated an asymmetrically-modified nickel catalyst.An EPMA (SEM-EDX) study indicated that RNi-U consisted of a fairly pure nickel surface of homogeneous size.Tartaric acid-NaBr-modified RNi-U (TA-NaBr-MRNi-U) showed a high enantio-differentiating ability as well as reactivity in the hydrogenation of prochiral ketones such as 1,3-diones and 3-oxoalkanoic acid esters.
Towards the Chemoenzymatic Synthesis of Lipid A
Sugai, Takeshi,Ritzen, Helena,Wong, Chi-Huey
, p. 1051 - 1058 (2007/10/02)
New procedures have been developed for the synthesis of the two important components of lipid A; one is the lipase-catalyzed resolution of 3-hydroxytetradecanoic acid in tetrahydrofuran using vinyl acetate and the other is the synthesis of the disaccharide moiety using glycosylphosphite as the glycosylating reagent.
New efficient methods for the synthesis and in-situ preparation of ruthenium(II) complexes of atropisomeric diphosphines and their application in asymmetric catalytic hydrogenations
Heiser,Broger,Crameri
, p. 51 - 62 (2007/12/18)
A new synthetically useful method for the synthesis of the diphosphine ruthenium dicarboxylato complexes (P-P)Ru(O2CR)2(R= CF3 and CH3) is presented, which uses the easily accessible complex (COD)2Ru2(μ-O2CCF3)4 as starting material. This complex as well as (COD)(Ru(ηO2CCH3)2 and (COD)2Ru2Cl4(NCCH3) have been shown to be suitable precursor complexes for the in-situ preparation of ruthenium(II) dicarboxylato and dichloro complexes of atropisomeric diphosphines, respectively. The high efficacy of the preformed and in-situ generated ruthenium complexes as precatalysts is demonstrated in asymmetric hydrogenations of allylic alcohols, enamides, and a β-keto ester.
