新型磺酰胺手性配体的合成与表征

以天然L-缬氨酸为手性源,通过保护氨基、缩合、去保护、还原、酰化等简单步骤合成了3种新型的磺酰胺类手性配体.该类反应具有后处理简单、反应温和、产率高等优点.并利用1HNMR、13CNMR、ESI/MS对合成的目标产物进行了表征及结构确认,并初步探索了该类型配体在催化二乙基锌对醛的不对称加成反应中的应用.     

玳玳花精油成分的研究

采用水蒸汽蒸馏法对玳玳花进行提取制得精油,应用GC—FTIR和GC—MS对精油进行分析,经研究共分离确认组分28种,玳玳花精油主要成份是芳樟醇、乙酸芳樟酯、芋烯、β-蒎烯、罗勒烯、α-松油醇、香叶醇、乙酸香叶酯、橙花醇、乙酸橙花酯、橙花叔醇、金合欢醇等。并用手性色谱柱对芳樟醇进行手性分离,芳樟醇中（-）-芳樟醇（左旋）占90％以上,同时对玳玳进行植物学鉴定,玳玳的学名为Citrus aurantium L．’Daidai’。     

吡啶羧酸类配位聚合物的研究进展

作为潜在的新型功能材料,吡啶羧酸类配位聚合物近年来得到科学家的普遍关注.本文主要对吡啶羧酸类配位聚合物在手性拆分和催化、分子磁体、非线性光学方面的研究进行了综述,列举了近年来这类配位聚合物的研究成果和开发进展,并对其发展前景作出了展望.     

(6S)2,6-二氨基-4,5,6,7-四氢苯并噻唑的制备

以2-氨基-6-乙酰氨基-4,5,6,7-四氢苯并噻唑氢溴酸盐为原料,经过水解反应除去乙酰基,然后用L(+)酒石酸成盐、解析拆分后合成了制备普拉克索的重要中间体-(-)-(6S)2,6-二氨基-4,5,6,7-四氢苯并噻唑,总收率>75%,并对合成产物进行1H NMR、IR表征分析。     

Spontaneous Deracemization

Chirality can emerge spontaneously from racemizing samples in a remarkably efficient manner. The effect results from the stochastic generation of an excess of one enantiomer in the solid and subsequent amplification of the initial material to the bulk. In this review we shall give examples showing how this effect has proved to be an inspiration for the emergence of chirality from chiral materials, and even for the preparation of pharmaceutically important intermediates. While spontaneous deracemization should produce either enantiomer randomly, the kind of system that demonstrates the phenomenon is very prone to the induction of one handedness with extremely small quantities of chiral inducer, which makes the process exploitable in certain cases. This kind of deracemization is the epitome of the origin, transfer and amplification of chirality.     

Synthesis of chiral stationary phase via surface‐initiated atom transfer radical polymerization of vinylated cellulose 3,5‐dimethylphenylcarbamate

A polysaccharide‐immobilized chiral stationary phase (CSP) was prepared by the surface‐initiated atom transfer radical polymerization (SI‐ATRP), in pyridine, of cellulose 2,3‐bis(3,5‐dimethylphenylcarbamate), having a polymerizable vinyl group, on the surface of SiO₂ support. The successful preparation of the CSP was confirmed via Fourier transform infrared spectroscopy, field‐emission scanning electron microscopy, X‐ray photoelectron spectroscopy, elemental analysis and thermal analysis. The chiral recognition ability of the prepared CSP was evaluated with high‐performance liquid chromatography using 10 racemates with various mobile phases of hexane/alcohol, hexane/tetrahydrofuran and hexane/chloroform. As a result, this CSP prepared using SI‐ATRP can be used in tetrahydrofuran and chloroform solutions as eluents. Copyright © 2011 Society of Chemical Industry     

生物拆分制备(S)-α-乙基-2-氧-1-吡咯烷乙酸工艺研究

耐酪氨酸冢村氏菌(Tsukamurella tyrosinosolvens)E105可选择性催化(R,S)-α-乙基-2-氧-1-吡咯烷乙酸乙酯生物拆分制备左乙拉西坦关键手性中间体(S)-α-乙基-2-氧-1-吡咯烷乙酸.通过单因素实验和响应面法对菌株产酶培养条件进行优化,并考察含酶静息细胞催化制备(S)-α-乙基-2-氧-1-吡咯烷乙酸的反应过程.结果表明:最优产酶培养条件为装液量30%,接种量4%,发酵36h;培养基组成为葡萄糖17.70g/L,酵母膏16.53g/L,NH4Cl 9.5g/L,K2HPO42g/L,KH2PO41g/L,NaCl 0.6g/L,MgSO4·7H2O 0.5g/L,初始pH值7.32.在优化条件下,酶活力为19.33U/g,细胞干重达4.13g/L,分别较优化前提高了32.6%和60.1%.当细胞加量为30g/L,底物浓度60mmol/L,反应体系为300mL,拆分24h后,产率和ee值分别为48%和99%,(S)-α-乙基-2-氧-1-吡咯烷乙酸浓度达28.8mmol/L,较优化前提高了32.1%.     

Qualitative Analysis of the Helical Electronic Energy of Inherently Chiral Calix[4]arenes: An Approach to Effectively Assign Their Absolute Configuration

For all microhelices on aromatic rings of inherently chiral calix[4]arene, an expression was derived from one approximation and one hypothesis on the basis of the electron-on-a-helix model of Tinoco and Woody as follows: , where µ = 1 for the right-handed microhelix and µ = −1 for the left-handed microhelix; and H and K are constant and greater than zero. The expression correlates microhelical electronic energy (E) with the atom polarizability difference (Δα) on both microhelix ends, which intuitively and clearly shows the impact of helical substituent polarizability on helical electronic energy. The case analysis almost entirely proves that the qualitative analysis of the helical electronic energy of inherently chiral Calix[4]arenes with the expression is scientific and can be used to effectively assign their absolute configuration.     

Advanced Monte Carlo simulations of the adsorption of chiral alcohols in a homochiral metal‐organic framework

Grand canonical Monte Carlo (GCMC) simulations with configurational biasing were used to study the enantioselective adsorption of four alkanols in a homochiral metal‐organic framework, known as hybrid organic‐inorganic zeolite analogue HOIZA‐1. Conventional GCMC simulations are not able to converge satisfactorily for this system due to the tight fit of the chiral alcohols in the narrow pores. However, parallel tempering and parallel mole‐fraction GCMC simulations overcome this problem. The simulations show that the enantioselective adsorption of the different (R,S)‐alkanols is due to the specific geometry of the chiral molecules relative to the pore size and shape. © 2014 American Institute of Chemical Engineers AIChE J, 60: 2324–2334, 2014