新的手性膦配体的合成及其在苯乙烯不对称氢甲酰化反应中的应用

以甘露醇为原料合成了两个新的手性膦配体,并用这些新的手性膦配体和醋酸钯原位生成的催化剂体系催化苯乙烯的不对称氢甲酰化反应,当配体为手性膦氧配体(DDPPIO)时得到S构型的2-苯基丙醛的e.e.为21.9％,用手性膦硫配体(DDPPIS)作配体时得到S构型的2-苯基丙醛的e.e.11.2％。     

Synthesis of chiral polymers and its application in asymmetric reduction

Two new cinchona alkaloids copolymers (PMA‐BQTP and PMA‐QN) have been synthesized by copolymerization and their complexes (PMA‐BQTP‐PdCl₂ and PMA‐QN‐PdCl₂) have been prepared. Their structures were characterized by FTIR, GPC, and element analysis. The catalytic activity of PMA‐QN‐PdCl₂ in the heterogeneous catalytic asymmetric reduction of aromatic ketone by sodium borohydride was studied. The results showed that the polymer complex catalyzed the reduction of aromatic ketone to get alcohol in high optical yield, but their catalytic efficiency was largely dependent on the aromatic ketone and solvent system, which relate to the accessibility of the catalytic active site. And the PdCl₂/polymeric alkaloid complex can be simply recovered at the end of the reaction by centrifugation and then reused without serious losing of activity or enantioselectivity. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 148–152, 2007     

Synthesis of chiral polymers having camphanediol moieties and their applications on the optical resolution of some racemates

Optically active exo-exo-2,3-camphanediol (CPO) (3) was synthesized from (+)-camphor. Chiral polymers poly(CPO-co-TDI) ( 6 ) and poly(CPO-co-IPDI) ( 7 ) were synthesized by the step polymerization of chiral compound CPO ( 3 ) with toluene-2,4-diisocyanate (TDI) and isophorone diisocyanate (IPDI). To investigate the stereo structure of the chiral polymers, two kinds of model compounds, exo-exo-2,3-di[(phenylamido)oxy]camphane ( 4 ) and exo-exo-2,3-di[(propylamido)oxy]camphane ( 5 ), related to polymers ( 6 ) and ( 7 ) were synthesized. Chiroptical characteristics and stereo structures of the chiral polymers were investigated using a circular dichroic spectrometer. The results obtained in this investigation suggest that the chiral polymers ( 6 ) and ( 7 ) have no one-handed helix conformation. The optical resolution ability as chiral adsorbent for HPLC of the chiral polymers was investigated. It was found that chiral polymers ( 6 ) and ( 7 ) are effective for the optical resolution of some racemates. © 1995 John Wiley & Sons, Inc.     

Functional monomers and polymers, 98. Asymmetric induction by chiral polymers containing bornyl groups

In order to determine the catalytic ability of the polymers containing chiral bornyl groups to the asymmetric induction, the asymmetric addition reaction of dodecanethiol to isopropenyl methyl ketone was studied using synthetic chiral polymers having pendant bornyl groups, in comparison with the case of using a monomeric model compound, i.e. d-bornyl acetate, and also poly(methyl methacrylate). It was found that the polymers having chiral borynl groups were effective for the asymmetric induction, and the optical yield depended on the bornyl group content in the polymers.     

Reactive monomers and polymers containing chiral groups

N-(p-methylstyryl)-(1R,2S)-ephedrine is prepared by alkylation of p-chloromethylstyrene under conditions which do not favor quaternization. A series of Copolymerization reactions confirm that the new chiral monomer and styrene copolymerize in random fashion with r₁=1.09 and r₂=0.98. The optical rotation of the copolymers does not vary linearly with composition. Applications of the copolymer include its use as chiral ligand for asymmetric synthesis or as a separation medium.     

Transparent chiral polymers for optical applications

Optically active chiral polymers and copolymers of cholesteryl methacrylate have been studied for use in optical applications including plastic optical fibers. Homopolymers of chiral cholesteryl methacrylate with differing molecular weights and copolymers with methyl methacrylate were synthesized by free‐radical copolymerization in tetrahydrofuran using azobisisobutyronitrile at 67°C for 26 h. All polymers were characterized for molecular weight, glass‐transition temperature, optical rotation, transparency, and refractive index and solution blended to test for compatibility with poly(methyl methacrylate). Such chiral materials are of particular interest because they offer useful polarization properties without requiring bulk orientation of the molecules. This makes it possible to produce low cost optical elements such as circularly birefringent or circularly polarizing optical elements with potential applications in polarization manipulations and sensing. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 58–65, 2005     

手性磺酰胺的合成及在苯乙酮的不对称氢转移反应中的应用

以辛可宁为原料,经Mitsunobu反应合成了9-氨基(9-脱氧)表辛可宁,然后分别与8-喹啉磺酰氯、苯磺酰氯、对甲基苯磺酰氯、对氯苯磺酰氯反应,合成了4个手性磺酰胺化合物.对这些磺酰胺在苯乙酮的不对称氢转移反应中的催化性能进行了考察,在80℃下反应,当n(苯乙酮):n(手性磺酰胺Ru(Ⅱ)配合物):n(氢氧化钾)=50:1:2.5时,获得的最大转化率为96.0%.     

高分子聚合物担载手性金属卟啉作为不对称催化剂的研究进展

手性金属卟啉经常用作催化合成对映体纯的化合物,但在实际应用中却有很多不利因素,如稳定性差、催化剂回收困难等。使用聚合物作为载体可以很好地解决这些问题。现常用的载体聚合物有电引发聚合物膜、大分子树脂和大孔分子筛,这些极大地提高了手性金属卟啉的催化性能。     

Synthesis of superabsorbent polymers by irradiation and their applications in agriculture

The superabsorbent polymers (SAPs) were synthesized by grafting copolymerization of acrylic acid and acrylamide onto starch by using γ‐ray radiation technique and poly(ethylene glycol) (PEG) as a crosslinker. The samples were characterized by IR spectroscopy. The effect of various synthetic parameters such as irradiation dose, irradiation dose rate, monomer concentration, monomer/starch ratio, and PEG content were studied. The effects of different drying methods on water absorbency of the SAPs were also studied. The experimental results showed that the water absorbency of the SAPs depends largely on the specific conductance of water when the specific conductance is below 500 μs/cm. The water retention of sand and soil was enhanced by using the SAPs. Effects of the SAPs on the germination of seeds and growth of young plants were investigated. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1748–1755, 2004     

Synthesis and characterization of poly(p-phenylene vinylene) polymers containing the quinoxaline group

Summary Novel poly (p-phenylenevinylene) polymers containing the quinoxaline group were prepared by the Horner-Wadsworth-Emmons reaction of the various diphosphonic acid diethyl ester with a dialdehyde monomer. The spectral properties of products so obtained were characterized by UV-visible and fluorescence spectroscopy. The UV-visible absorbance of these polymers showed absorption bands at ca. 432∼440 nm, which corresponding to the π-π* transition of the conjugated system. Their maximum fluorescence appeared at ca. 488 ∼ 498 nm. The resulting polymers showed greenish blue emission in solution and an orange emission in solid state. Received: 13 December 2002/Revised version: 27 February 2003/ Accepted: 1 March 2003 Correspondence to Jae Yun Jaung     

Synthesis and characterization of novel monomers and polymers containing chiral (−)-menthyl groups

To investigate the steric effects of chiral menthyl groups on the induction of cholesteric liquid crystals and the sensitivity of the photoisomerizable azobenzene derivatives, a series of chiral monomers and a photoisomerizable chiral azobenzene derivative with various spacers end-capped with (−)-menthyl group were synthesized. The structures of the novel chiral compounds synthesized in this investigation were identified using ¹³C NMR, FTIR, and elemental analysis. The phase transition temperatures of the chiral compounds were investigated using X-ray diffraction, differential scanning calorimetry, and polarizing optical microscopy. The thermogravimetric characteristics, the glass-transition temperatures (T_g) and the weight-average molecular weights (M_w) of the homopolymers were also evaluated. Polymers containing chiral menthyl groups with a biphenyl segment were found to reveal high thermal resistance. However, the existence of the steric hindered menthyl group disturbed the arrangement of chiral monomers leading to the disappearance of liquid crystal phases. The specific optical rotation of the synthesized monomers and polymers were also evaluated. The effect of the synthesized chiral compounds, monomers and photoisomerizable azobenzene derivative on the induction of the cholesteric liquid crystal films was investigated. The morphological network structure of the polymer matrix inside a liquid crystal cell was studied using a scanning electron microscope (SEM). The phototuning ability of the AzoM on the cholesteric liquid crystals was also established.     

Synthesis and characterization of chiral polyacrylates and their applications as positive tone photoresists

To estimate the effects of diastereomeric copolymers as photoresists, diastereomeric copolymers containing chiral and racemic bornyl methacrylates (BMAs) were synthesized. Both alicyclic BMAs were synthesized from (?)‐borneol and (±)‐borneol, and then copolymerized with t‐butyl methacrylate (t‐BMA), tetrahydro‐pyranyl methacrylate (THPMA), and α‐methacryloxy‐γ‐butyrolactone (MABL). The glass transition temperature of the copolymers was found to increase with an increase in the content of alicyclic bornyl groups in the copolymers. To investigate the effect of both the alicyclic butyrolactone and the bornyl groups on photosensitivity, thermal property, and etching resistance, the synthesized alicyclic copolymers were used to prepare photoresists with photoacid generators. The sensitivity and the contrast of the photoresists were calculated. This investigation demonstrated that the existence of alicyclic butyrolactone and bornyl groups increases the etching resistance of photoresists. It was also found that high stereo hindered bornyl structures disturb and restrict the mobility of the polymer chain, leading to an increase in the thermal stability of the polymers. A real pattern recording of photoresists with PR3 composition was performed; an optimal sensitivity of 20 mJ/cm² and resolution of 1 μm of positive tone photoresists with 1 μm thickness was achieved. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

含磷多孔有机聚合物的合成及其在多相催化中的应用

含磷多孔有机聚合物不仅具有发达的孔隙和表面结构,还具有很强的可调变性和可修饰性,在多相催化中有着广泛的应用前景。目前还没有概述含磷多孔有机聚合物的制备及其在多相催化中应用的综述,本文对该领域近十年来的研究进展进行了归纳和梳理。指出含磷多孔有机聚合物的合成方法发展十分迅速,包括偶联缩聚、锂盐参与的缩聚、Friedel-Crafts缩聚、溶剂热烯烃聚合、Scholl缩聚、酚醛聚合、醛胺缩合、聚吡喃盐的磷代以及多段式聚合等。基于其骨架中含有大量膦配体,含磷多孔有机聚合物能负载一系列金属化合物制成负载型金属纳米颗粒催化剂,甚至单原子或单位点金属催化剂。表明聚合物基催化剂中,膦配体不仅能诱导金属在聚合物中均匀分布,并且在调控金属的表面电子性质和位阻性质等方面发挥重要作用,进而对催化剂的活性和选择性产生影响。     

Enantioface differentiation by chiral polymers containing dimethylaminobornyl moieties

Chiral monomers cis,endo-3-dimethylamino-2-bornyl methacrylate (DABM) and N,N-dimethyl[cis,endo-2-(2-vinyloxy-ethoxy)-3-bornyl]amine (DVEBA) were synthesized from (+)-camphor. The homopolymerization of both DABM and DVEBA, and the copolymerization of both chiral monomers with achiral methylmethacrylate (MMA) and styrene (St) were carried out with 2,2-azobisisobutyronitrile (AIBN) in various organic solvents. Effects of temperature, solvents, reagent molar ratio and reaction time on the polymerizations were studied. Dependences of the feeding concentration and reaction conditions on the specific rotation of the chiral copolymers were investigated. Enantioface differentiation by using the chiral polymers having dimethylaminobornyl moieties synthesized in this investigation were investigated. Effects of temperature and solvent on the asymmetric induction were also studied. © 1994 John Wiley & Sons, Inc.     

Synthesis of polymers from chiral monomers in chiral liquid crystals

Polymer prepared from a monomer ((S)‐configuration at stereogenic center) in a cholesteric liquid crystal (CLC) medium consisting of chiral molecules in (R)‐configuration, a three‐dimensional (3D) chiral continuum, exhibits intense Cotton effect compared to polymer prepared in the CLC with (S)‐configuration. This result can be explained by intermolecular interaction between the monomer and the CLC medium in the polymerization process. The intramolecular twisted structure along the polymer chain (secondary structure) and the helical aggregation between the polymer chains (intermolecular structure and tertiary structure) induced by the liquid crystal medium as 3D chiral continuum are discussed. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Construction of achiral/chiral coordination polymers with helical structures based on an imidazole-based dicarboxylate ligand containing the trifluoromethyl group

Two new coordination polymers, {[Pb(μ₂-H₂TFMIDC)₂-(μ₂-H₂O)]·H₂O}_n (H₃TFMIDC = 2-(trifluoromethyl)-4,5-imidazole dicarboxylic acid, 1) and [Ba(μ₂-H₂TFMIDC)(μ₄-H₂TFMIDC)(H₂O)]_n (2), were constructed under hydrothermal/solvothermal conditions. Compound 1 is an achiral 3D framework based on irregular helical chains and displays a 6-connected pcu network topology. Compound 2 exhibits a 3D chiral framework based on homochiral 1D helical chains with a (4,8)-connected network topology. The luminescence properties of compounds 1–2 were also investigated.     

Synthesis of polymers containing acetamide structure and their use as phase transfer catalyst

Summary N-Methyl-N-(p-vinylbenzyl) acetamide was synthesized by the reaction of p-chloromethylstyrene with N-methylacetamide in the presence of sodium hydride. This monomer was readily polymerized or copolymerized with styrene by AIBN. The resulting polymers served as effective phase transfer catalysts for several nucleophilic substitution reactions under liquid-liquid biphase conditions. The catalytic activity was discussed on the terms of cation binding ability of the polymers and activation of anions caused by the desolvation on hydrophobia region of the polymers.     

Synthesis of new polymers containing tannin

A novel method for preparation of immobilized tannin on polyethylene has been suggested. A tannin-containing polymer was prepared by radiation-induced graft polymerization of glycidyl methacrylate onto porous polyethylene, followed by coupling tannin with the produced epoxide group. Reaction conditions for preparing immobilized tannin, such as the reaction temperature, pH, and the molar ratio of tannin to the epoxide group were investigated. The tannin content of the tannin-containing porous polyethylene was 20%, which is approximately equivalent to that of the conventional cellulose-based immobilized tannin. The adsorption isotherm for immobilized tannin and ferrous ion was determined.     

Synthesis and characteristics of chiral polymers with camphanediol moieties

Optically active exo,exo-2,3-camphanediol (CPO) was synthesized from (+)-camphor. The chiral polymers poly(CPO-co-TDI) and poly(CPO-co-IPDI) were synthesized by step polymerization of chiral compound CPO with toluene-2,4-diisocyanate (TDI) and isophorone diisocyanate (IPDI). Effects of solvents, reaction time and temperature on the polymerization were investigated. To investigate the stereo structure of the chiral polymers, two kinds of model compounds, exo-exo-2,3-bornylene N,N′-diphenyldicarbamate and exo,exo-2,3-bornylene N,N′-dipropyldicarbamate, related to the prepared polymers were synthesized. Chiroptical characteristics and stereo structures of the chiral polymers were investigated by using a circular dichroic spectrometer. Effects of temperature and solvents on the specific rotation of the chiral polymers were evaluated. The results obtained in this investigation suggest that the synthesized chiral polymers have no one-handed helix conformation.     

Synthesis and applications of stimuli-responsive hyperbranched polymers

Benefiting from their responsiveness and adaptability, the stimuli-responsive polymers have been widely investigated and exploited in the various fields, such as environmental monitoring, electronics, photonics, controlled drug delivery, medical imaging and diagnostics. These potential applications have greatly promoted the development of advanced functional materials, and meanwhile set higher requirements for the smart materials in the aspects of the spatial structures, diverse linkages and variable functions. However, the linear functional polymers can not satisfy all the requirements of the multi-dimensional molecular design and acute sensitiveness due to the architectural limitation. Accordingly, stimuli-responsive hyperbranched polymers (HBPs) have been drawing more and more attention in recent years owing to their unique globular void-containing topological structure featured with a large number of terminal functional groups and branches, lower solution or melt viscosity, and better solubility. Therefore, design and synthesis of stimuli-responsive HBPs provide a robust tool for controlling the structure transition and creating the hierarchical sensitivity driven by different triggers. In this review, the developments and recent advances of preparation procedures, performance control and promising applications of various stimuli-responsive HBPs have been comprehensively summarized. Besides, the developing trend of stimuli-responsive HBPs is also discussed. It can be found that stimuli-responsive HBPs with different synthetic strategies and diverse performances have manifested more and more versatile applications.