α-苯乙胺拆分2-取代丁二酸1-叔丁酯

在乙酸乙酯中,对2-取代丁二酸1-叔丁酯和手性α-苯乙胺形成的非对映体盐进行化学拆分,得到了(R)-和(S)-2-取代丁二酸1-叔丁酯.     

Encapsulation studies of hydrogen on cadmium exchanged zeolite rho at atmospheric pressure

Temperature programmed diffusion (TPDi) has been used to study the encapsulation of hydrogen in cadmium exchanged Cs-rho zeolite. The amount encapsulated after 2 h has been observed to be about 71 μmol/g at 50°C and 1 atm. This amount is over 30 times the amount of hydrogen encapsulated with NaX or NaA at 37°C for the same time and pressure. Upon increasing the encapsulation temperature to 100°C, the amount encapsulated increased to 161 μmol/g (2 h of encapsulation). At 200°C, the encapsulate is about 620 μmol/g, for the same pressure and time. With increasing temperature, more than one peak is seen in the TPDi spectra, revealing the availability of more than one site¹ for the encapsulation. 3 peaks are observed in TPDi spectra for the encapsulation at 200°C - at 107, 295 and 345°C. Large encapsulated amounts of hydrogen arise from blocking effects caused by the presence of cations (cadmium and/or cesium). Experiments for encapsulation of hydrogen on H-rho (hydrogen exchanged zeolite rho) show negligible uptake of hydrogen, proving that the presence of either the cadmium ion (5.05 Cd²⁺ per unit cell) or the cesium ion (1.87 Cs⁺ per unit cell) or both is directly responsible for the encapsulation of hydrogen.

For encapsulation at 200°C, possible migration of the encapsulate among the sites seems to occur with encapsulation time. This could explain the relative changes in the intensities of the 3 peaks in the TPDi spectra for the encapsulation at 200°C.     

Preparation and characterization of novel optically active polyurethanes containing 1,1′‐binaphthol

Novel optically active polyurethanes (BPUs) based on chiral 1,1′‐binaphthol were synthesized via direct hydrogen transfer addition polymerization. The polymers were analyzed by FTIR, ¹H NMR, DSC‐TGA, CD spectra.The results showed that the specific rotation [α]²⁵_D were ?78.0° and +54.6° for the S‐BPU and R‐BPU respectively, and these polymers showed better thermal stability. The circular dichroism spectra of the chiral polymers were almost identical except that they gave opposite signals at each wavelength, and the infrared emissivity values of the S‐BPU and R‐BPU were 0.618 and 0.682, they displayed low infrared emissivity. Meantime the polymers implanted with PEG group exhibit better solubility, however thermal stability reduced to some extent. Some properties of the new optically active polyurethanes were reported. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

(2R,3S)-3-羟基-天冬氨酸盐酸盐的合成

介绍了羟基天冬氨酸的合成,以D-酒石酸二乙酯为原料,与氯化亚砜反应成亚磺酸类化合物,再与叠氮化钠发生开环反应后,催化加氢还原后得到羟基天冬氨酸二乙酯,经皂化反应后得到目标产物,4步反应的总收率为42%。     

(2R, 3S)-3-羟基-天冬氨酸盐酸盐的合成研究

本文介绍了羟基天冬氨酸合成的,以D-酒石酸二乙酯为原料,与氯化亚砜反应成亚磺酸类化合物,再与叠氮化钠发生开环反应后,催化加氢还原后得到羟基天冬氨酸二乙酯,经皂化反应后得到目标产物,四步反应的总收率为42.04%。     

Chiral platinum(II) metallointercalators with potent in vitro cytotoxic activity

Four platinum(II) metallointercalating complexes of 1,10-phenanthroline (phen) with the chiral ancillary ligands trans-R,R- and trans-S,S-1,2-diaminocyclohexane (R,R- and S,S-dach, respectively), and N,N'-dimethyl-R,R- and N,N'-dimethyl-S,S-1,2-diaminocyclohexane (Me(2)-R,R-dach and Me(2)-S,S-dach, respectively) have been synthesised and characterised. The crystal structure of [Pt(Me(2)-S,S-dach)(phen)](ClO(4))(2)1.5 H(2)O (C(20)H(26)Cl(2)N(4)O(9.5)Pt) has been determined; orthorhombic, space group P2(1)2(1)2(1)(No. 19), a=23.194(8), b=25.131(9), c=8.522(3) A. In vitro cytotoxic assays (IC(50)) in the human bladder cancer cell line 5637 and in the murine leukemia L1210 cell line revealed that [Pt(S,S-dach)(phen)](ClO(4))(2) (0.091 and 0.13 microM, respectively) and [Pt(R,R-dach)(phen)](ClO(4))(2) (0.54 and 1.50 microM, respectively) were more cytotoxic than cisplatin (0.31 and 0.50 microM, respectively) and considerably more cytotoxic than their methylated counterparts, [Pt(Me(2)-R,R-dach)(phen)](ClO(4))(2) and [Pt(Me(2)-S,S-dach)(phen)](ClO(4))(2) (both>23 microM). Chiral discrimination for [Pt(S,S-dach)(phen)](ClO(4))(2) over its R,R-enantiomer was observed in all 13 cancer cell lines investigated. Moreover, [Pt(S,S-dach)(phen)](ClO(4))(2) was more active than cisplatin in all cell lines tested and shows only partial cross-resistance to cisplatin in two cisplatin resistant cell lines.     

Molecular structure modulated properties of azobenzene-substituted polydiacetylene LB films: Chirality formation and thermal stability

Langmuir-Blodgett (LB) films of three novel azobenzene-substituted diacetylene monomers (DA1, DA2 and DA3) were fabricated and their optical and chiroptical properties were investigated in detail by ultraviolet-visible (UV-vis) spectra and circular dichroism (CD) spectra. Achiral DA1 molecules could form chiral LB films through overcrowded packing of the azobenzene moiety, while achiral DA2 and DA3 molecules not. When exposed to left-or right-handed circular polarized UV light (CPUL), striking left- or right-handed (opposite) CD signals for azobenzene chromophores and polydiacetylene chains were observed for the polymerized DA1 (PDA1) and DA2 (PDA2) LB films. However, DA3 LB films could hardly be polymerized in this case, and only striking opposite CD signals for azobenzene chromophores could be observed. It was demonstrated that the intermolecular steric hindrance and irregular arrangement of azobenzene chromophores were not favorable for the topo-polymerization and chirality formation of polydiacetylenes backbone. Further, the effects of thermal treatment on the supramolecular chirality of above three LB films were studied. Strong collective noncovalent interactions (π-π stacking) were believed to be responsible for the thermal stability of chiral supramolecular assemblies.     

Does Pheromone Biology of Lambdina athasaria and L. pellucidaria Contribute to Their Reproductive Isolation?

Recently, 7-methylheptadecane and 7,11-dimethylheptadecane have been reported as sex pheromone components of both spring hemlock looper (SHL), Lambdina athasaria, and pitch pine looper (PPL), Lambdina pellucidaria. Our objective was to test the hypothesis that SHL and PPL are reproductively isolated, in part, through species specificity in: (1) absolute configuration of pheromone components, (2) diel periodicity of pheromonal communication, and/or (3) seasonal flight period. In coupled gas chromatographic-electroantennographic detection (GC-EAD) analyses of stereoselectively synthesized (7S)- and (7R)-7-methylheptadecane [7S; 7R] as well as (7S,11S)-, (7R,11R)-, and (meso-7,11)-7,11-dimethylheptadecane [7S,11S; 7R,11R; meso-7,11], only 7S and meso-7,11 elicited responses by male SHL and PPL antennae. In field experiments, male SHL and PPL were attracted only to lures containing 7S plus meso-7,11. In hourly recordings of trap-captured males, SHL and PPL in their respective habitats were trapped between 24:00 and 03:00 hr. Capture of both SHL and PPL in pheromone-baited traps throughout June indicated overlapping seasonal flight periods. These findings of identical absolute configuration of pheromoal components, diel periodicity of pheromonal communication, and overlap of seasonal flight periods support synonymy of SHL and PPL. Finite taxonomic classification of PPL and SHL must await careful assessment of further criteria, such as morphometrics, molecular comparisons and ecological analyses.     

己基乙二胺-TFS型质子化离子液体与水分子间氢键相互作用的研究

通过前期实验研究,己基乙二胺-三氟甲磺酸([HHex][TFS])型质子化离子液体(protic ionic liquid,PIL)的极性部位具有两个氨基,亲水性较强,能够与水混溶90%(质量)(H₂O/ PIL)以上。因此利用密度泛函理论(density functional theory,DFT),在M06-2X/6-311G(d,p)的水平下,对 [HHex][TFS]与H₂O分子间形成的氢键作用进行了研究。设计了[HHex][TFS]分别与nH₂O (n = 1, 2, 6) 相结合的构型,并得到了较稳定构型共8种(S1~S8),计算了其分子间的相互作用能(ΔE ₀ ^BSSE)、分子振动频率(Δν)、二阶微扰能、电子密度(ρ _c)以及Laplace值(?² ρ _c)。分析结果显示,[HHex][TFS]与水分子间形成了较强的氢键,[HHex][TFS]与H₂O结合数量增加,构型中氢键相互作用增强,即S4(n=1)＜S6(n=2)＜S8(n=6)。     

A set of multicolored Photinus pyralis luciferase mutants for in vivo bioluminescence applications

Error-prone PCR was used to isolate Photinus pyralis luciferase mutants producing bright light in the red-orange region of the spectrum. All mutations were clustered in the beta5-alpha10-beta6 region of N-terminal subdomain B and appear to affect bioluminescence color by modulating the position of the Ser314-Leu319 mobile loop with respect to the putative active site. Two red variants (Q283R and S284G) and one orange mutant (S293P) contained a single substitution. Although the remaining orange variant contained two mutations, L287I mainly contributed to the color change. Emission spectra collected on whole cells at pH 7.0 revealed that while a single peak of lambdamax approximately 605 nm accounts for red light production by the Q283R and S284G variants, orange light results from the contribution of two peaks of lambdamax approximately 560 and 600 nm. All spectra underwent a red-shift when cells were assayed under acidic conditions, whereas a blue-shift was observed at pH 8.0, indicating that the internal pH of Escherichia coli is close to the external pH shortly after imposition of acid or alkaline stress. In addition, changes in assay pH led to bimodal emission spectra, lending support to the idea that bioluminescence color is determined by the relative contribution of yellow-green and red-orange peaks. The set of multicolored luciferase mutants described here may prove useful for a variety of applications including biosensing, pH monitoring, and tissue and animal imaging.     

Domain-selective ligand-binding modes and atomic level pharmacophore refinement in angiotensin I converting enzyme (ACE) inhibitors

Somatic ACE (EC 3.4.15.1), a Zn(II) metalloproteinase, is composed of functionally active N and C domains resulting from tandem gene duplication. Despite the high degree of sequence similarity between the two domains, they differ in substrate and inhibitor specificity and in their activation by chloride ions. Because of the critical role of ACE in cardiovascular and renal diseases, both domains are attractive targets for drug design. Putative structural models have been generated for the interactions of ACE inhibitors (lisinopril, captoril, enalaprilat, keto-ACE, ramiprilat, quinaprilat, peridoprilat, fosinoprilat, and RXP 407) with both the ACE_C and the ACE_N domains. Inhibitor-domain selectivity was interpreted in terms of residue alterations observed in the four subsites of the binding grooves of the ACE_C/ACE_N domains (S1: V516/N494, V518/T496, S2: F391/Y369, E403/R381, S1': D377/Q355, E162/D140, V379/S357, V380/T358, and S2': D463/E431, T282/S260). The interactions governing the ligand-receptor recognition process in the ACE_C domain are: a salt bridge between D377, E162, and the NH(2) group (P1' position), a hydrogen bond of the inhibitor with Q281, the presence of bulky hydrophobic groups in the P1 and P2' sites, and a stacking interaction of F391 with a benzyl group in the P2 position. In ACE_N these interactions are: hydrogen bonds of the inhibitor with E431, Y369, and R381, and a salt bridge between the carboxy group in the P2 position of the inhibitor and R500. The calculated complexes were evaluated for their consistency with structure-activity relationships and site-directed mutagenesis data. A comparison between the calculated interaction free energies and the experimentally observed biological activities was also made. Pharmacophore refinement was achieved at an atomic level, and might provide an improved basis for structure-based rational design of second-generation, domain-selective inhibitors.     

手性7-氨基脱氢松香酸乙酯的合成及表征

以脱氢松香酸为起始原料,通过酯化、氧化、手性辅剂亚胺化、还原以及酸解脱除手性辅剂等反应获得光学纯的 7 -（S）- 氨基脱氢松香酸乙酯 6a 和 7 -（R）- 氨基脱氢松香酸乙酯 6b。产物结构通过 1H NMR、13C NMR、MS 和 HRMS 进行表征,绝对构型经 X-ray 单晶衍射确定。     

酒石酸锑钾的制备

以酒石酸氢钾和三氧化二锑为原料,制备了酒石酸锑钾,用元素分析、IR、XRD进行了表征。X射线粉末衍射数据指标化结果表明,所得产品为单斜晶系,晶胞参数为:a=0.825 0 nm,b=1.604 6 nm,c=1.773 6 nm,β=96.65°。确定了合成反应条件:n(三氧化二锑)∶n(酒石酸氢钾)∶n(水)=1.05∶2.0∶92,反应时间4.5 h,温度90℃,产率为86.8%。     

手性双哌啶氨基醇衍生物的合成

由简单的烷基胺与丙烯酸甲酯为原料,经Michael加成、Dieckmann环合、脱羧得到三种N-烷基-4-哌啶酮。这些N-烷基-4-哌啶酮分别与(R)-(-)-2-氨基-1-丁醇和多聚甲醛进行Mannich反应,再经黄鸣龙还原得到三种新的具有手性的双哌啶氨基醇衍生物。采用1H NMR、13C NMR、IR、MS对目标产物的结构进行了表征,并对其旋光度进行了测定。Mannich反应优化条件为:甲醇回流温度下反应,物料摩尔比为n(N-烷基-4-哌啶酮)∶n((R)-2-氨基-1-丁醇)∶n(多聚甲醛)=1∶1.2∶2.5。     

On the transformation of (S)-2-hydroxypropylphosphonic acid into fosfomycin in Streptomyces fradiae--a unique method of epoxide ring formation

(1S,2S)- and (1R,2S)-2-hydroxy-[1-D(1)]propylphosphonic acid were synthesised from (1S,2S)-2-benzyloxy-[1-D(1)]propanol, which was obtained by horse liver alcohol dehydrogenase catalysed reduction of the corresponding aldehyde. When (1S,2S)-2-hydroxy-[1-D(1)]propylphosphonic acid was fed to Streptomyces fradiae, the deuterium was retained to the same extent in fosfomycin (cis-epoxide) and its co-metabolite trans-epoxide. Removal of the hydrogen (deuterium) atom from the C-1 atom of deuterated 2-hydroxypropylphosphonic acids is a stereospecific process (the hydrogen atom of (S)-2-hydroxypropylphosphonic acid is pro-R). The formation of the O--C-1 bond of fosfomycin occurs with net inversion of configuration, the formation of the O--C-1 bond of the trans-epoxide with net retention.     

Catalytic Non‐Enzymatic Kinetic Resolution

While tremendous advances have been made in asymmetric synthesis, the resolution of racemates is still the most important industrial approach to the synthesis of chiral compounds. The use of enzymes for the kinetic resolution (KR) of racemic substrates to afford enantiopure compounds in high enantioselectivity and good yield has long been a popular strategy in synthesis. However, transition metal‐mediated and more recently organocatalyzed KRs have gained popularity within the synthetic community over the last two decades due to the progress made in the development of chiral catalysts for asymmetric reactions. Many catalytic non‐enzymatic procedures have been developed providing high enantioselectivity and yield for both products and recovered starting materials. Indeed, the non‐enzymatic KR of racemic compounds based on the use of a chiral catalyst is presently an area of great importance in asymmetric organic synthesis. The goal of this review is to provide an update on the principal developments of catalytic non‐enzymatic KR covering the literature since 2004. This review is subdivided into seven sections, according to the different types of compounds that have been resolved through catalytic non‐enzymatic KR, such as alcohols, epoxides, amines, alkenes, carbonyl derivatives, sulfur compounds and ferrocenes. Abbreviations: Ac: acetyl; acac: acetylacetone; AQN: anthraquinone; Ar: aryl; Atm: atmosphere; BINAM: 1,1′‐binaphthalenyl‐2,2′‐diamine; BINAP: 2,2′‐bis(diphenylphosphanyl)‐1,1′‐binaphthyl; BINEPINE: phenylbinaphthophosphepine; BINOL: 1,1′‐bi‐2‐naphthol; Bmim: 1‐butyl‐3‐methylimidazolium; Bn: benzyl; Boc: tert‐butoxycarbonyl; Box: bisoxazoline; BSA: bis(trimethylsilyl)acetamide; Bu: butyl; Bz: benzoyl; c: cyclo; CBS: Corey–Bakshi–Shibata; Cbz: benzyloxycarbonyl; COD: cyclooctadiene; COE: cyclooctene; Cy: cyclohexyl; Dba: (E,E)‐dibenzylideneacetone; DBU: 1,8‐diazabicyclo[5.4.0]undec‐7‐ene; DCC: N,N′‐dicyclohexylcarbodiimide; de: diastereomeric excess; DEAD: diethyl azodicarboxylate; Dec: decanyl; DHQD: dihydroquinidine; Difluorphos: 5,5′‐bis(diphenylphosphino)‐2,2,2′,2′‐tetrafluoro‐4,4′‐bi‐1,3‐benzodioxole; DIPEA: diisopropylethylamine: DKR: dynamic kinetic resolution; DMAP: 4‐dimethylaminopyridine; DMSO: dimethyl sulfoxide; DNA: deoxyribonucleic acid; DOSP: N‐(dodecylbenzenesulfonyl)prolinate; DTBM: di‐tert‐butylmethoxy; ee: enantiomeric excess; Et: ethyl; equiv.: equivalent; Fu: furyl; Hex: hexyl; HIV: human immunodeficiency virus; HMDS: hexamethyldisilazide; KR: kinetic resolution; L: ligand; LDA: lithium diisopropylamide; MAO: methylaluminoxane; Me: methyl; Ms: mesyl; MTBE: methyl tert‐butyl ether; Naph: naphthyl; nbd: norbornadiene; NBS: N‐bromosuccinimide; NIS: N‐iodosuccinimide; Pent: pentyl; Ph: phenyl; Piv: pivaloyl; PMB: p‐methoxybenzoyl; Pr: propyl Py: pyridyl; r.t.: room temperature; s: selectivity factor; Segphos: 5,5′‐bis(diphenylphosphino)‐4,4′‐bi‐1,3‐benzodioxole; (S,S′,R,R′)‐Tangphos: (1S,1S′,2R,2R′)‐1,1′‐di‐tert‐butyl‐(2,2′)‐diphospholane; TBS: tert‐butyldimethylsilyl; TBDPS: tert‐butyldiphenylsilyl; TCCA: trichloroisocyanuric acid ; TEA: triethylamine; TEMPO: tetramethylpentahydropyridine oxide; THF: tetrahydrofuran; Thio: thiophene; Tf: trifluoromethanesulfonyl; TMS: trimethylsilyl; Tol: tolyl; Ts: 4‐toluenesulfonyl (tosyl)     

The synthesis,photophysical and thermal properties of new anthrapyrimidine colorants

The thermal and photostability of novel anthrapyrimidine‐containing colorants obtained by the condensation of various substituted aromatic amines with 6‐bromo‐7H‐benzo[e]perimidin‐7‐one are described. The colorants were characterised by proton nuclear magnetic resonance, elemental analysis and mass spectra. Thermogravimetric analysis showed that these colorants are thermally stable up to 250 °C. The UV–visible absorption spectra of the colorants were studied in solvents of differing polarity; the colorants exhibited slight positive solvatochromism. The photostability studies in dimethyl sulphoxide solvent were recorded by monitoring photodegradation of the colorants spectrophotometrically using a standard calibration curve. All the colorants exhibited excellent photostability. The light fastness study of two colorants in polypropylene showcases their ability as useful colorants for plastics.     

Asymmetric synthesis and receptor pharmacology of the group II mGlu receptor ligand (1S,2R,3R,5R,6S)-2-amino-3-hydroxy-bicyclo[3.1.0]hexane-2,6-dicarboxylic acid-HYDIA

The asymmetric synthesis and receptor pharmacology of (1S,2R,3R,5R,6S)-2-amino-3-Hydroxy-bicyclo[3.1.0]hexane-2,6-dicarboxylic Acid (+)-9 (HYDIA) and a few of its O-alkylated derivatives are described. The key step of the synthesis utilizes Sharpless' asymmetric dihydroxylation (AD-beta) for the kinetic resolution of a bicyclic racemic precursor olefin. In contrast to the bicyclic glutamate analogue LY354740, which is a potent and selective agonist for the group II metabotropic glutamate receptors (mGluRs), these new conformationally restricted and also hydroxylated or alkoxylated glutamate analogues are potent and selective antagonists for the group II mGluRs.     

平行-连续法合成沙奎那韦

采用平行-连续法合成了H IV蛋白酶抑制剂沙奎那韦。在中间体(S)-4-氨基-4-氧代-2-(喹啉-2-羧酰胺基)丁酸的合成中,由喹哪啶-2-羧酸与亚硫酰氯反应得其酰氯作为活化剂,最佳反应条件为:回流8 h,收率95.0%;采用水介质合成了(S)-4-氨基-4-氧代-2-(喹啉-2-羧酰胺基)丁酸,收率82.0%。在硅胶存在下,(S)-1-〔(S)-2-环氧乙烷〕-2-苯基乙基氨基甲酸苄酯和(3S,4aS,8aS〕-N-叔丁基-十氢异喹啉-3-羧酰胺室温反应72 h,得(2S,3R)-4-〔(3S,4aS,8aS)-3-(叔丁氨甲酰基)-十氢异喹啉〕-3-羟基-1-苯基丁基-2-氨基甲酸苄酯,不经提纯,加入Pd/C〔w(Pd)=10%〕催化剂室温下与H2反应12 h脱去保护基,反应完毕后以乙腈重结晶即得另一中间体(3S,4aS,8aS)-2-〔(2R,3S)-3-氨基-2-羟基-4-苯基丁基〕-N-叔丁基-十氢异喹啉-3-羧酰胺,收率87.0%;两个中间体连接时,使用便宜、常见的N-羟基琥珀酰亚胺,收率82.0%。     

R-3,5-(双三氟甲基)苯乙醇不对称合成工艺

以[RuCl2(C10H14)2]2为催化剂、(1S,2R)-(-)-1-氨基-2-茚醇为配体,3,5-双三氟甲基苯乙酮在异丙醇中发生不对称氢化还原反应得到R-3,5-(双三氟甲基)苯乙醇。在反应时间6 h、温度50℃、n(催化剂)∶n(配体)=1∶2.5、底物浓度0.095 7 mol/L的条件下,产品的转化率达99.32%,选择性(ee)达91.2%。用FTIR和1HNMR进行了表征。