共查询到20条相似文献,搜索用时 31 毫秒
1.
Dr. Jian-Dong Zhang Ya-Wen Chang Rui Dong Xiao-Xiao Yang Dr. Li-Li Gao Dr. Jing Li Dr. Shuang-Ping Huang Dr. Xing-Mei Guo Dr. Chao-Feng Zhang Dr. Hong-Hong Chang 《Chembiochem : a European journal of chemical biology》2021,22(1):124-128
Optically active β-amino alcohols are very useful chiral intermediates frequently used in the preparation of pharmaceutically active substances. Here, a novel cyclohexylamine oxidase (ArCHAO) was identified from the genome sequence of Arthrobacter sp. TYUT010-15 with the R-stereoselective deamination activity of β-amino alcohol. ArCHAO was cloned and successfully expressed in E. coli BL21, purified and characterized. Substrate-specific analysis revealed that ArCHAO has high activity (4.15 to 6.34 U mg−1 protein) and excellent enantioselectivity toward the tested β-amino alcohols. By using purified ArCHAO, a wide range of racemic β-amino alcohols were resolved, (S)-β-amino alcohols were obtained in >99 % ee. Deracemization of racemic β-amino alcohols was conducted by ArCHAO-catalyzed enantioselective deamination and transaminase-catalyzed enantioselective amination to afford (S)-β-amino alcohols in excellent conversion (78–94 %) and enantiomeric excess (>99 %). Preparative-scale deracemization was carried out with 50 mM (6.859 g L−1) racemic 2-amino-2-phenylethanol, (S)-2-amino-2-phenylethanol was obtained in 75 % isolated yield and >99 % ee. 相似文献
2.
L. Saikia J. K. Satyarthi R. Gonnade D. Srinivas P. Ratnasamy 《Catalysis Letters》2008,123(1-2):24-31
A novel application of Fe–Zn double metal cyanide complexes as solid, acid catalysts for regioselective synthesis of β-amino alcohols under solvent-free conditions via ring-opening of epoxides with amines is reported for the first time. The conversion of epoxides to β-amino alcohols is nearly 100%. In the reaction with styrene oxide, regioselective β-amino alcohol formation is higher with aromatic than with aliphatic amines. Strong Lewis acidic Zn2+ ions in the catalyst are probably the active sites in this reaction. 相似文献
3.
Prof. Michael Müller 《化学,工程师,技术》2013,85(6):795-808
Tertiary alcohols are found as a motif in many pharmaceuticals and natural products. Elucidation of their biosynthesis is thus a good starting point for the identification of enzymes for the synthesis of chiral tertiary alcohols. To date, however, relatively few enzymatic methods for such syntheses have been established in biotechnological processes. Whereas secondary alcohols can be efficiently synthesized via the (asymmetric) reduction of ketones, a generally applicable method for the enzymatic synthesis of tertiary alcohols has been more difficult to identify. Herein, a survey of the biocatalytic methods for the synthesis of (chiral) tertiary alcohols is presented. Advantages and disadvantages of the respective methods are discussed from a synthetic point of view. 相似文献
4.
Shanthakumar Sithambaram Ranjit Kumar Young-Chan Son Steven L. Suib 《Journal of Catalysis》2008,253(2):269-277
Tandem processes involving catalysts can offer unique and powerful strategies for converting simple starting materials into more complex products in a single reaction vessel. Imines were synthesized directly from alcohols via a tandem catalytic process using manganese octahedral molecular sieves (OMS-2) as catalyst. The synthesis proceeds through two steps: an oxidation of the alcohols to carbonyls followed by the nucleophilic attack by an amine on the carbonyl to form the imine. OMS-2 acts as a bifunctional catalyst and catalyzes two mechanistically distinct processes in a single reaction vessel under the same conditions. Conversions up to 100% were obtained for benzylic alcohols with this efficient, environmentally friendly catalytic reaction. The advantages of this process are that the intermediates need not be isolated and the catalysts can be reused upon simple filtration without loss of activity. 相似文献
5.
S. Morita H. Narita T. Matoba M. Kito 《Journal of the American Oil Chemists' Society》1984,61(10):1571-1574
Triacylglycerols were synthesized from 1,2-diacylglycerol and fatty acids by lipase entrapped in phosphatidylcholine reverse
micelles in n-hexane. In the reaction system without reverse micelles, however, 1,2-diacylglycerol was hydrolyzed into 2-monoacylglycerol
and fatty acid, and triacylglycerol was not synthesized. The maximum activity of synthetic reaction was obtained at Wo=10
(Wo=mol water/mol surfactant), which was the water content of this reverse micellar system. Though the optimal pH of theR. delemar lipase reaction is about pH 5.6 in a bulk water system, the enzyme was active for triacylglycerol synthesis at pH’s from
5 to 9 in the reverse micellar system. For the synthesis of triacylglycerols, lauric, myristic, palmitic, stearic, oleic and
arachidic acids were effectively used as the fatty acid substrate. 2-Monoacylglycerol was also effective as a substrate of
triacylglycerol synthesis. Furthermore, 1,2-diacylglycerol could be replaced by several kinds of aliphatic alcohols as fatty
acid acceptors in the reverse micellar system. In this case, those alcohols with chain length more than 4 carbons were effectively
used for ester formation. 相似文献
6.
An efficient synthesis of (S)-α-amino oleic acid was developed. The fully protected FA derivative was obtained in four steps starting from methyl (2S)-2-[bis(tert-butoxycar-bonyl)amino]-5-oxopentanoate. These steps are (i) olefination of the starting aldehyde with the appropriate phosphonate
anion, (ii) hydrogenation of the double bonds, (iii) controlled reduction of ω-ethyl ester to an aldehyde in the presence
of α-methyl ester, and (iv) a Wittig reaction of the latter aldehyde with the suitable ylide. Free α-amino oleic acid was
prepared after deprotection of the amino group followed by saponification in a total yield of 24%. N-tert-Butoxycarbonyl-protected amino oleic acid and the corresponding amino alcohol were prepared in high yield. The structures
of the products have been established by various spectroscopic techniques. 相似文献
7.
Laura Mendieta Anna Picó Dr. Teresa Tarragó Dr. Meritxell Teixidó Dr. Marcos Castillo Dr. Llorenç Rafecas Albert Moyano Prof. Dr. Ernest Giralt Prof. Dr. 《ChemMedChem》2010,5(9):1556-1567
Herein we present the design, synthesis, and evaluation of a structurally novel library of 20 peptidyl 3‐aryl vinyl sulfones as inhibitors of cathepsins L and B. The building blocks, described here for the first time, were synthesized in a highly efficient and enantioselective manner, starting from 3‐aryl‐substituted allyl alcohols. The corresponding vinyl sulfones were prepared by a new approach, based on a combination of solid‐phase peptide synthesis using the Fmoc/tBu strategy, followed by solution‐phase coupling to the corresponding (R)‐3‐amino‐3‐aryl vinyl sulfones as trifluoroacetate salts. The inhibitory activity of the resulting compounds against cathepsins L and B was evaluated, and the compound exhibiting the best activity was selected for enzymatic characterization. Finally, docking studies were performed in order to identify key structural features of the aryl substituent. 相似文献
8.
Although catalytic asymmetric synthesis has undergone tremendous growth in the last 30 years, chiral auxiliary-aided asymmetric synthesis continues to attract considerable attention. Chiral N- tert-butanesulfinamide, as pioneered by Ellman and co-workers, is undoubtedly one of the most efficient auxiliaries developed to date; it allows the preparation, through simple conversion, of a diverse range of enantiopure amines, which are ubiquitous in natural products and biologically active molecules. Following on from our studies of the SmI(2)-mediated asymmetric syntheses of alpha,gamma-substituted gamma-butyrolactones, we found that simple homocoupling of chiral N- tert-butanesulfinyl imines in the presence of SmI(2) produced enantiopure vicinal C2-symmetric diamines in high yield. In addition, C2-unsymmetric chiral diamines are readily prepared through SmI(2)-mediated cross-couplings of N- tert-butanesulfinyl imines and nitrones; these transformations represented the first successful examples of asymmetric cross-coupling between two different imine species. Subsequently, we discovered another useful reaction induced by SmI(2), the efficient cross-coupling of N- tert-butanesulfinyl imines and aldehydes, which provides ready access to enantiopure anti-1,2-amino alcohols. The synthetic applicability of this reaction was demonstrated through its use in the facile total syntheses of (3R,4S)-statine, d- erythro-sphinganine, (+)-CP-99,994, and (+)-L-733,060. The Zn/In-mediated allylation of chiral N- tert-butanesulfinyl imines yields homoallylic amines. After pondering the reaction mechanism, we developed optimal reaction conditions for reversing the stereogenic outcome, thereby allowing the preparation of enantiopure homoallylic amines of either handedness from single enantiomers of the (R)- or (S)-sulfinyl imine. When a benzoyl-substituted allyl bromide is used for allylation, the reaction proceeds smoothly to give 2-vinyl-substituted anti-1,2-amino alcohols in high yields and diastereoselectivities, another simple method for preparing enantiopure amino alcohols. We employed these reactions in the syntheses of enantiopure allylglycine, 3-allyl-isoindolinones, and (-)-cytoxazone. Further studies led to the discovery that the allylations of N- tert-butanesulfinyl aldimines can be performed in water. The reactions described in this Account are among the simplest and most efficient synthetic methods available for preparing enantio-enriched diamines, amino alcohols, homoallylic amines, and other amine derivatives. These reactions are additionally attractive because of the ready availability of the starting materials, the simplicity of the reaction conditions, and the high degree of stereochemical control. Their applications in the total syntheses of several biologically interesting molecules illustrate the versatility of these transformations; we hope that they will stimulate the development of new synthetic methods. 相似文献
9.
Constantin I. Tnase Constantin Drghici Miron Teodor Cproiu Anamaria Hanganu Gheorghe Borodi Maria Maganu Emese Gal Lucia Pintilie 《International journal of molecular sciences》2021,22(13)
β-Ketophosphonates with pentalenofurane fragments linked to the keto group were synthesized. The bulky pentalenofurane skeleton is expected to introduce more hindrance in the prostaglandin analogues of type III, greater than that obtained with the bicyclo[3.3.0]oct(a)ene fragments of prostaglandin analogues I and II, to slow down (retard) the inactivation of the prostaglandin analogues by oxidation of 15α-OH to the 15-keto group via the 15-PGDH pathway. Their synthesis was performed by a sequence of three high yield reactions, starting from the pentalenofurane alcohols 2, oxidation of alcohols to acids 3, esterification of acids 3 to methyl esters 4 and reaction of the esters 4 with lithium salt of dimethyl methanephosphonate at low temperature. The secondary compounds 6b and 6c were formed in small amounts in the oxidation reactions of 2b and 2c, and the NMR spectroscopy showed that their structure is that of an ester of the acid with the starting alcohol. Their molecular structures were confirmed by single crystal X-ray determination method for 6c and XRPD powder method for 6b. 相似文献
10.
Jens Christoffers Heiko Oertling Necl
nal 《Advanced Synthesis \u0026amp; Catalysis》2000,342(6):546-553
Michael reactions of β‐keto esters 1a—1h with methyl vinyl ketone ( 2a ) catalyzed by FeCl3 · 6 H2O (5 mol%) proceed with up to 99% yield. Conversion of β‐keto esters 1a—1e derived from chiral alcohols with 2a result in only very low diastereoselectivities (max. de 20%). A bis‐β‐keto ester 1i and a bis‐vinyl ketone 2b — both valuable monomers for poly‐Michael reactions — are synthesized from common starting materials in up to gram quantities. 相似文献
11.
以TiCl4和无水AlCl3为原料,以无水低碳醇为氧供体通过非水解溶胶-凝胶法低温合成了钛酸铝,研究了无水低碳醇种类及用量对钛酸铝合成反应的影响.结果表明:当氧供体按反应式化学计量比用量加入时,在750℃能合成出钛酸铝,其中以乙醇的合成效果最好,异丙醇次之,正丁醇的效果较差;采用甲醇和叔丁醇作氧供体,由于它们的化学活性过大而引发水解反应,不能低温(750 ℃)合成钛酸铝.当醇用量超过化学计量比时,则合成效果显著下降;当醇用量低于化学计量比时,改变乙醇的用量对合成效果影响不明显,而减少异丙醇和正丁醇用量可显著提高钛酸铝的合成效果. 相似文献
12.
A novel homologous series of 1-N-l-tryptophanglycerol-ether surfactants was synthesized and characterized. The precursor compounds, 3-alkyloxy-1-chloropropan-2-ols,
were prepared from epichlorohydrin and aliphatic alcohols with alkyl chain lengths of 9–16 carbon atoms. Tryptophan was then
attached to the monosubstituted glycerol backbone from its α-amino group through an α-NH-C bond. Structural assignment of
the new compounds was made on the basis of elemental analysis and spectroscopic data. Critical micelle concentrations of the
new surfactants, as well as the negative logs of the surfactant concentrations required to reduce the surface tension of the
solvent by 20 mN/m (pC
20) and the interfacial areas occupied by the surfactant molecules, were calculated from aqueous surface tension measurements
using the Wilhelmy plate technique. 相似文献
13.
14.
Eiko Wada Masato Handa Koreyoshi Imamura Takaharu Sakiyama Shuji Adachi Ryuichi Matsuno Kazuhiro Nakanishi 《Journal of the American Oil Chemists' Society》2002,79(1):41-46
N-Medium- and long-chain acyl-l-amino acids were enzymatically synthesized from the corresponding l-amino acids and fatty acids using a reverse hydrolysis. Enzymes that are suitable for the synthetic reaction of N-acyl-l-amino acids were screened on the basis of hydrolytic activity toward N-lauroyl-l-glutamic acid as an indicator. Acylase I from pig kidney (EC 3.5.1.14) showed the highest N-acyl-l-amino acid hydrolytic activity among 57 commercially available enzymes tested. Acylase I effectively catalyzed the synthesis
of N-lauroyl-l-amino acids except for N-lauroyl-l-proline and N-lauroyl-l-tyrosine in a glycerol-water system. Under the optimized reaction conditions, N-lauroyl-l-arginine and N-lauroyl-l-glutamic acid were obtained in conversions of 82 and 44%, respectively. The equilibrium constants calculated from the conversion
obtained were 5.6, 15.4, 18.0, and 39.4 for the syntheses of N-lauroyl-l-glutamic acid, Nα-lauroyl-l-lysine, N-lauroyl-l-glutamine, and N-lauroyl-l-methionine, respectively. N-Acyl-l-arginines with myristic acid and palmitic acid as the fatty acid were also synthesized using acylase I. 相似文献
15.
《Journal of Sulfur Chemistry》2013,34(6):590-595
A new and facile synthetic route is proposed for the synthesis of some novel phenothiazines (5a–5g) based on the reaction of 2-amino substituted benzenethiols with p-tert-butyl phenol in good yield. The newly synthesized compounds were characterized by IR, 1H NMR and mass spectral studies. Their antimicrobial activities against three strains of bacteria: Bacillus subtilis, Bacillus megaterium, Escherichia coli, and two strains of fungi: Aspergillus niger and Aspergillus oryzae, were investigated. 相似文献
16.
A highly stable benzimidazolylidene based N-heterocyclic carbene (NHC) ruthenium catalyst was prepared starting with readily accessible starting materials. Under inert gas atmosphere and in air the catalyst showed high activity for the direct synthesis of esters from primary alcohols and of amides from primary alcohols and amines. Di-, tri-, and oligo-amides were obtained by using specific starting materials. 相似文献
17.
D. H. Sreenivasa Rao Dr. Santosh Kumar Padhi 《Chembiochem : a European journal of chemical biology》2019,20(3):371-378
Hydroxynitrile lyase (HNL)-catalysed stereoselective synthesis of β-nitro alcohols from aldehydes and nitroalkanes is considered an efficient biocatalytic approach. However, only one S-selective HNL—Hevea brasiliensis (HbHNL)—exists that is appropriate for the synthesis of (S)-β-nitro alcohols from the corresponding aldehydes. Further, synthesis catalysed by HbHNL is limited by low specific activity and moderate yields. We have prepared a number of (S)-β-nitro alcohols, by kinetic resolution with the aid of an R-selective HNL from Arabidopsis thaliana (AtHNL). Optimization of the reaction conditions for AtHNL-catalysed stereoselective C−C bond cleavage of racemic 2-nitro-1-phenylethanol (NPE) produced (S)-NPE (together with benzaldehyde and nitromethane, largely from the R enantiomer) in up to 99 % ee and with 47 % conversion. This is the fastest HNL-catalysed route known so far for the synthesis of a series of (S)-β-nitro alcohols. This approach widens the application of AtHNL for the synthesis not only of (R)- but also of (S)-β-nitro alcohols from the appropriate substrates. Without the need for the discovery of a new enzyme, but rather by use of a retro-Henry approach, it was used to generate a number of (S)-β-nitro alcohols by taking advantage of the substrate selectivity of AtHNL. 相似文献
18.
19.
The influence of acidity, alkyl chain length of alcohols, synthesis temperature and time on the molecular sieve synthesis by adding alcohols to the system for the SBA-1 synthesis were studied. Upon increasing the concentration of alcohols (CmH2m+1OH) in the mixture of tetraethyl orthosilicate (TEOS), cetyltriethylammonium bromide (CTEABr), HCl and H2O, highly ordered P63/mmc and p6mm phases were formed when m = 2 and 3 ≤ m ≤ 6, respectively. The amount of HCl was an important factor for the phase-selection under acidic conditions. 相似文献
20.
Ryoko Kawahara Ken‐ichi Fujita Ryohei Yamaguchi 《Advanced Synthesis \u0026amp; Catalysis》2011,353(7):1161-1168
An efficient and environmentally benign catalytic system for the synthesis of various organic amines catalyzed by the water‐soluble and air‐stable (pentamethylcyclopentadienyl)‐iridium‐ammine iod‐ ide complex, [Cp*Ir(NH3)3][I]2 (Cp*=pentamethylcyclopentadienyl), has been developed. A wide variety of secondary and tertiary amines were synthesized by the N‐alkylation reactions of theoretical equivalents of amines with alcohols in water under air without a base. The synthesis of cyclic amines was also achieved by the N‐alkylation of benzylamine with diols. Furthermore, the recycle use of the present water‐soluble Cp*Ir catalyst was accomplished. 相似文献