Synthesis, Crystal Structure and Properties of a Chiral 3D Supramolecular Coordination Polymer [Co(HL)·(DMF)]_n from 5-(Imidazol-1-ylmethyl)isophthalic Acid

A chiral supramolecular coordination polymer, [Co（HL）·（DMF）]n（1）, with helical chains from a flexible ligand 5-（imidazol-1-ylmethyl）isophthalic acid（H2L） has been obtained under hydrothermal conditions and characterized by elemental analysis, powder X-ray diffraction（PXRD）, IR, Uv/vis spectra, thermal gravimetric analyses（TGA） and also by single-crystal X-ray diffraction. It crystallizes in hexagonal, space group P6522 with a = 8.8109（3）, b = 8.8109（3）, c = 71.771（3） , γ = 120°, V = 4825.3（3） -3, Z = 6, Mr = 695.55, Dc = 1.436 g/cm-3, Rint = 0.0684, F（000） = 2166, the final R = 0.0923 and w R = 0.2697 for 3056 observed reflections（I 2σ（I））. The title coordination polymer 1 shows a chiral layered structure based on right-handed helix chains. Such layers are associated together through hydrogen-bonding interactions to form a 3D supramolecular framework.

Preparation and spectroscopic, and thermal decomposition kinetic studies of europium(Ⅲ) complex [Eu(HNBD)_3] (HNBD: 1-(6-hydroxy-1-naphthyl)-1,3-butanedione)

The complex of Eu（IH） with 1-（6-hydroxy- 1-naphthyl）- 1,3-butanedione （HNBD） was prepared for the first time and characterized by elemental analysis, IR, UV, fluorescence spectrum, and DTA-TG-DTG techniques. The IR and UV-visible spectra showed that Eu（Ⅲ） ion was coordinated to the HNBD ligand. The fluorescence spectrum showed the presence of Eu^3＋ characteristic emission. The TG-DTA-DTG curves showed that the thermal decomposition of the anhydrous complex was a two-stage process and the final residue was Eu2O3. The thermal decomposition kinetic parameters of the complex were evaluated from TG-DTG data by using three kinds of integral methods （Coat-Redfem equation, Horowitz and Metzger equation, Madhusudanan-Krishnan-Ninan equation）. The kinetic parameters of the first stage are E^＊ = 164.02 kJ.moll, A = 1.31 × 10^15 s^-l, AS^＊= 42.27 J·K^-l·mol^-l, △H^＊ = 159.51 kJ·mol^-l, △G^＊= 136.54 kJ·mol^-l, and n = 3.1, those of the second stage are E^＊= 128.52 kJ·mol^-l, A = 1.44× 106 s^-1, △S^＊= - 136.89 J·K^-l·mol^-l, △H^＊ = 120.41 kJ·mol^-l, △G^＊= 283.85 kJ·mol^-l, and n = 1.1.

Synthesis and Crystal Structure of 4,4'-(4-(1-Naphthyl)-4-phenyl-1,3-butadienylidene)-bis[N,N-diethylbenzenamine]

The title compound （C40H42N2） has been synthesized by the reaction of l-（l- naphthyl）-l-phenyl-3-chloropropylene and bis（4-（diethylamino） phenyl）methanone, and characterized by IR, ^1H NMR, MS and X-ray diffraction analysis. The crystal belongs to the monoclinic system, space group P21/c with a = 17.047（3）, b = 10.807（2）, c = 18.494（4） A, β = 105.727（4）°, V= 3279.4（11） A^3, Mr = 550.76, Z = 4, Dc = 1.115 g/cm^3,μ（MoKa） = 0.085 mm^-1, F（000） = 1184, the final R = 0.0625 and wR = 0.1384 for 2276 observed reflections （1 〉 2σ（I））. X-ray analysis reveals that the butadiene fragment adopts a planar cisiod conformation and makes a dihedral angel of 69.4（2）° with the naphthalene ring.

An Improved and Efficient Preparation of the Chiral NAD(P)H Model (S_s)-1-Benzy1-3-(p-tolylsulfinyl)-1,4-dihydropyridine

An improved procedure for the preparation of China, BAD(P)H model. (S_s)- 1 -benzyl-3- (p-tolylsulfinyl)-1.4-dihydropyridine with satisfactary chemical yield and excellent enantiopurity is reported.

手性1-(1-萘基)乙胺的制备及其药物应用最新进展

详细综述了手性1-(1-萘基)乙胺的化学拆分、酶拆分和不对称合成的最新研究进展,及其在药物合成方面的应用,并展望了其制备工艺的发展趋势。

Pocket Modification of x-Amine Transaminase AtATA for Overcoming the Trade-Off Between Activity and Stability Toward 1-Acetonaphthone

Amine transaminases(ATAs)catalyze the asymmetric amination of prochiral ketones or aldehydes to their corresponding chiral amines.However,the trade-off between activity and stability in enzyme engineering represents a major obstacle to the practical application of ATAs.Overcoming this trade-off is important for developing robustly engineered enzymes and a universal approach for ATAs.Herein,we modified the binding pocket of co-ATA from Aspergillus terreus(AtATA)to identify the key amino acid residues controlling the activity and stability of AtATA toward 1-acetonaphthone.We discovered a structural switch comprising four key amino acid sites(R128,V149,L182,and L187),as well as the"best"mutant(AtATAD224K/V149A/L182 F/L187F;termed M4).Compared to the parent enzyme AtATAD224K(AtATAPa),M4 increased the catalytic efficiency(k_(cat)/K_(m)^(1-acetonaphthone),where kcatis the constant of catalytic activities and is 10.1 min^(-1),K_(m)^(1-acetonaphthoneis) Michaelis-Menten constant and is 1.7 mmol·L^(-1))and half-life(t1/2)by 59-fold to 5.9 L·min^(-1)·mmol-1and by 1.6-fold to 46.9 min,respectively.Moreover,using M4 as the biocatalyst,we converted a 20 mmol·L^(-1)aliquot of 1-acetonaphthone in a 50 mL scaled-up system to the desired product,(R)-(+)-1(1-naphthyl)ethylamine((R)-NEA),with 78%yield and high enantiomeric purity(R>99.5%)within 10 h.M4 also displayed significantly enhanced activity toward various 1-acetonaphthone analogs.The related structural properties derived by analyzing structure and sequence information of robust ATAs illustrated their enhanced activity and thermostability.Strengthening of intramolecular interactions and expansion of the angle between the substratebinding pocket and the pyridoxal 5’-phosphate(PLP)-binding pocket contributed to synchronous enhancement of ATA thermostability and activity.Moreover,this pocket engineering strategy successfully transferred enhanced activity and thermostability to three other ATAs,which exhibited 8%-22%sequence similarity with AtATA.This research has important implications for overcoming the trade-off between ATA activity and thermostability.

Synthesis of (4S)-4-Carboxyl-1-oxoperoxovanatranes

(4S)-4-Carboxyl-1-oxoperoxovanatrane and (4S)-3-methyl-4-carboxyl-1-oxoperoxovanatrane were synthesized from the reaction of potassium vanadate. hydrogen peroxide with L-N, N-bis (2-hydroxyethyl) serine or L-N. N-bis (2-hydroxyethyl) threonine in water.

Synthesis and Crystal Structure of 4-(Dichloroacetyl)-1-oxa-4-azaspiro[4.5]decane

The title compound 4-(dichloroacetyl)-1-oxa-4-azaspiro[4. 5] decane (CAS number 71526-07-3, C10H15Cl2NO2, Mr= 252.13) was obtained by the reaction of dichloroacetic acid with 1-oxa-4-azaspiro[4. 5] decane. The crystal is of monoclinic, space group P21ln with the unit cell constants: a = 5.9619(4),b= 10.0066(8), c = 20.0986(4) A,β = 90.194(3)°, V= 1199(4) A3,Z = 4, Dc= 1.397 g/cm3, F(000) = 528, μ(MoKα) = 0.522 mm-1, R = 0.0611 and wR = 0.1656 for 1276 observed reflections (I > 2σ(I)). X-ray analysis reveals that the cyclohexyl adopts a chair conformation and the compound is a chiral one.

外消旋2-羟基-3-甲氧基-3,3-二苯基丙酸的手性拆分研究

研究并优化了标题化合物的手性拆分工艺,获得其单一的S型异构体。以(S)-4-硝基-1-苯乙胺盐酸盐为手性拆分剂,与标题化合物生成非对映异构体,利用两者溶解性差异来进行手性拆分,得到中间体(S)-2-羟基-3-甲氧基-3,3-二苯基丙酸(S)-4-硝基-1-苯乙胺盐,经酸性游离后得到产物(S)-2-羟基-3-甲氧基-3,3-二苯基丙酸。对溶剂量、拆分剂的量、缚酸剂的量以及重结晶条件进行了考察,同时对手性拆分剂进行了回收。结果表明,以100 g标题化合物为起始原料,20倍体积的无水乙醇为溶剂,1.5倍物质的量的三乙胺为缚酸剂并使用0.75倍物质的量的拆分剂进行拆分时,得到了较好的产率(40.6%)和光学纯度(82.8%e.e.),经进一步重结晶达到质量要求(e.e.>99.00%)。该工艺具有操作简便、产品成本低且质量较高的优点,适用于工业化生产。

Synthesis of New Chiral [2-（1-Hydroxyalkyl）pyrrolidino]methylferrocenes and Application to the Catalytic Asymmetric Addition of Diethylzinc to Arylaldehydes

A series of new optically active [2-（1-hydroxyalkyl）pyrrolidino]methylferrocenes were conveniently prepared from commercially available L-proline and ferrocenecarboxylic acid. The crystal structure of key intermediate was obtained. They were then applied to catalyze enantioselective addition of diethylzinc to arylaldehydes with enantioselectivity up to 99%. The effects of the ligand structures on the enantioselectivity were also studied.

Synthesis of Agomelatine by One-pot Catalytic Hydrogenation and Acetylation with NiO

Nano-NiO and bulk NiO were prepared from Ni(AC)_2·4 H_2O by coordination precipitation using aqueous ammonia and by a solid state reaction, respectively. The nickel oxide particles were characterized by X-ray Diffraction(XRD) and scanning electron microscopy(SEM). The results indicate that nano-sized NiO has a crystal phase with a standard face-centered cubic lattice structure, with a mean particle diameter of about 10 nm. The evaluation of the activity of nickel oxide nanoparticles in the catalytic hydrogenation of 7-methoxy-1-naphthylacetonitrile was carried out. The results demonstrate the efficient synthesis of the title compound by a one-pot catalytic hydrogenation and acetylation with NiO. The NiO nanoparticles displayed superior catalytic activity in the synthesis of agomelatine in the one-pot reaction.The total yield of agomelatine is over 81.8% with a purity of 99.2%, as determined by HPLC. The structure of agomelatine was confirmed by IR, MS, and 1 H NMR analysis.

Synthesis,Characterization and Structure of Chiral Amino Acids and Their Corresponding Amino Alcohols with Camphoric Backbone

Chiral amino acids and their corresponding amino alcohols bearing camphoric backbone were prepared from D-（＋）-camphoric imide and characterized by infrared, elemental analysis, ESI-MS, and NMR measurements. Among them, one intermediate （1S,3R）-3-amino-2,2,3- trimethyl cyclopentane-1-carboxylic acid hydrochloride 3 was structurally elucidated by X-ray diffraction techniques. Versatile intermolecular hydrogen bonding interactions observed in its packing structure result in a two-dimensional framework.

Kinetic Resolution of 2-Chloro-1-（3,4-dichlorophenyl）ethanol by Lipase-Catalyzed Transesterification

Kinetic resolution of racemic 2-chloro-1-（3,4-dichlorophenyl）ethanol was performed by free Alcaligene sp. lipase-catalyzed irreversible transesterification affording the （R）-isomer with ≥95% ee and the （S）-isomer with ≥90% ee. The activity of lipase Alcaligene sp. strongly depends on the basicity of the reaction system, and an organic base such as triethylamine can enhance the activity of the lipase and enantioselectivity markedly.

手性流动相添加剂法拆分西那卡塞原料及中间体

以自制1-萘万古霉素(Na-VAN)为手性固定相(CSP),D-酒石酸(D-Tar)、L-酒石酸二乙酯(L-TADE)、D-酒石酸二乙酯(D-TADE)分别为手性流动相添加剂(CMPA),建立了西那卡塞原料1-(1-萘基)乙胺(化合物1)及西那卡塞中间体(化合物2)的高效液相色谱手性拆分方法。考察了流动相中醇类改性剂、CMPA对对映体分离的影响,初步探讨了手性识别机理。以Na-VAN为CSP,正相模式下,添加不同种类的CMPA,化合物1、化合物2均可获得一定程度的分离,其中以D-TADE为CMPA时,化合物1、化合物2获得最佳分离。结果表明,醇的分子体积、CMPA的立体构型均对手性分离有影响。

Comparative study of the extraction selectivity of PFO-BPy and PCz for small to large diameter single-walled carbon nanotubes

Semiconducting single-walled carbon nanotubes(s-SWCNTs)are fascinating materials for future electronic and optical applications.Conjugated polymer wrapping is one of the most promising methods for mass production of high purity s-SWCNTs.However,its chiral selectivity is relatively inferior to other s-SWCNT production methods.In this paper,the chiral selectivity of two polymers,poly[(9,9-dioctylfluorenyl-2,7-diyl)-alt-co-(6,6′-{2,2′-bipyridine})](PFO-BPy)and poly[9-(1-octylonoyl)-9H-carbazole-2,7-diyl](PCz),which are representatives of widely used polyfluorene and polycarbazole families,respectively,were comparatively studied.Both polymers exhibited high selectivity for a subset of existing chiral species in each of the commercially available raw SWCNT materials(CoMoCAT,HiPco,and arc-discharge)which cover a diameter range of 0.6–1.8 nm.Less chiral species were selected by PFO-BPy from small diameter(<1 nm)raw SWCNT materials,while more from large diameter(>1.2 nm)raw materials.High chiral purity(6,5)(>99%)and(7,5)(>75%)solutions were extracted by PFO-BPy and PCz from CoMoCAT materials,respectively.The different chiral angle and diameter selections for different raw materials by both polymers were ascribed to their different geometrical structures and related polymer-tube interactions.Our work provides indispensable information for better understanding the mechanism of polymer wrapping method and improving extraction of single chirality sSWCNTs.