(R)-1-[(S)-2-(二苯基膦)二茂铁基]乙基二(3,5-二甲基苯基)膦的合成

以乙酰基二茂铁为原料,经过钯催化氢化胺化及(R)-(+)-酒石酸拆分制备了(R)-1-二茂铁基乙基二甲胺(Ⅲ);Ⅲ与正丁基锂作用后,与二苯基氯化膦作用得到N,N-二甲基-(R)-1-[(S)-2-(二苯基膦)二茂铁基]乙胺(Ⅳ);Ⅳ与新制的二(3,5-二甲基苯基)膦烷发生构型保持的取代反应,得到双膦配体(R)-1-[(S)-2-(二苯基膦)二茂铁基]乙基二(3,5-二甲基苯基)膦(Ⅷ)。以乙酰基二茂铁计Ⅷ的总收率达19.5%,手性高效液相色谱分析其ee值达95%。     

浅析一种新型联苯类手性双膦配体的合成

简述了手性双膦配体的发展简史和新型手性双膦配体SEGPHOS的合成方法。在传统方法的基础上进行关键改进,5-溴胡椒环经格氏反应得到5-胡椒环基氧化二苯基膦、经二(异丙基)氨基锂化后用无水氯化铁氧化偶联合成关键中间体膦氧化物SEGPHOSO_2。"一锅煮"的方法简化了操作过程,特别是后处理更简单,粗品更容易纯化。使用(2S,3S)-二苯甲酰酒石酸进行拆分、最后经三氯氢硅烷还原得到手性双膦配体SEGPHOS。     

基于PPM的氨基酸型两性水溶性手性膦配体前体的合成

基于手性膦配体(2S,4S)-2-二苯膦甲基-4-二苯膦基四氢吡咯(PPM)合成了一种新型的氨基酸型两性水溶性手性膦配体的前体。首先以(2S,4S)-N-Boc-2-对甲苯磺酰氧甲基-4-对甲苯磺酰氧基四氢吡咯(1)为起始原料与二苯基膦化钠反应,再经膦硫化得到(2S,4S)-N-Boc-2-二苯硫膦甲基-4-二苯硫膦基四氢吡咯(2),收率67.2%;化合物2用过量的三氟乙酸处理脱去Boc保护基得到(2S,4S)-2-二苯硫膦甲基-4-二苯硫膦基四氢吡咯(3),收率94.0%;化合物3与N-Boc-L-天冬氨酸-4-苄酯缩合得到(2S,4S)-N-[(2′S)-2′-叔丁氧酰胺基-3′-苄氧酰基丙酰基]-2-二苯硫膦甲基-4-二苯硫膦基四氢吡咯(4),收率95.8%;化合物4再用三溴化硼脱去保护基得到目标产物(2S,4S)-N-[(2′S)-2′-氨基-3′-羧基丙酰基]-2-二苯硫膦甲基-4-二苯硫膦基四氢吡咯(5),收率54.2%。     

兰花根状茎催化手性还原反应及磁处理水对反应的影响

以组培兰花根状茎作为生物催化剂,以对硝基苯乙酮作为底物,生成了具有光学活性的手性芳香醇(S)-1-(4-硝基苯基)乙醇,反应收率61％,e.e.值93％.以0.8T磁感应强度的磁处理水作为反应的水相介质对此不对称还原反应有较好的促进作用,使收率提高至87％,但对产物构型和e.e.值没有显著影响.     

手性离子液体催化苯乙烯不对称氢甲酰化反应

手性是与生活休戚相关的一种自然属性,利用手性催化剂催化反应的进行是最有效的一种不对称催化合成反应方法。离子液体所具有的可设计性结构,以及黏度低、不易挥发、无异味、绿色环保等优良性质使其近年来受到化学工作者们的广泛青睐。将手性配体与功能化离子液体耦合,合成一种全新的具有不对称诱导和控制功能的手性离子液体催化剂,并用于反应考察其催化活性,得到了苯乙烯氢甲酰化的最优反应工艺条件为甲苯作溶剂,对叔丁基邻苯二酚作阻聚剂,反应温度60℃,合成气p(CO/H_2)=2 MPa,n(CO)∶n(H_2)=1,持续反应4 h。在该反应条件下,苯乙烯的转化率为84.9%,2-苯基丙醛收率为76%,e.e.值为84%。     

手性化合物的不对称催化氢化研究进展

在不对称催化氢化过程中起关键作用的是手性催化剂的结构,包括手性膦配体和中心过渡金属.简介了手性膦配体的过渡金属络合物的发展历程,即从单膦配体到双膦配体,从P-手性配体到C-手性配体,从双膦铑(Ⅰ)催化剂到双膦-钌(Ⅱ)催化剂;综述了各种新型手性配体催化剂在不同不对称催化氢化(包括C=C、C=O、C=N双键)中的应用,并对其最新进展及研究方向进行了探讨.     

生物催化不对称还原制备(R)-2-羟基-4-苯基丁酸

以克隆表达的乳酸脱氢酶(D-LDH)为催化剂来还原前手性化合物2-羰基-4-苯基丁酸(OPBA),制备重要的手性中间体(R)-2-羟基-4-苯基丁酸(R-HPBA)。通过考察影响反应的各因素,确定了反应pH、初始底物浓度,酶加量及NAD+加量等参数。最后,以分批补料的方式进行产物制备,4 h内即可完全转化100 mmol/L底物。经验证,所得产物的构型完全正确,且e.e值>99.9%。     

手性(Salen)Co催化(R)-3-氯氧化苯乙烯的合成

用手性(Salen)Co(Ⅱ)催化(±)-3-氯氧化苯乙烯的水解动力学拆分反应,以高收率得到光学纯的(R)-3-氯氧化苯乙烯(98.4%e.e)及(S)-1-(3-氯苯基)-1,2-乙二醇(89.5%,e.e)。     

铱催化体系不对称合成手性药物中间体(S)-(-)-1-苯基-1-丙醇

考察了苯丙酮在手性胺膦配体与[IrHCl2(COD)]2组成的催化体系下不对称转移氢化合成(S)-(-)-1-苯基-1-丙醇的反应,通过正交实验考察了反应温度、n(底物)∶n(铱催化剂)、n(铱催化剂)∶n(手性配体)和碱用量对反应的影响。结果表明,在异丙醇中,利用该体系催化苯丙酮反应6 h后,反应转化率可达94.5%,对映选择性(ee)达96.0%。     

(R)-(+)-2,2’-双[二(3,5-二甲苯基)膦]-1,1’-联萘的合成

三溴化磷为原料,与二(3,5-二甲基苯基)氧化膦反应,得到二(3,5-二甲基苯基)溴化膦,通过催化偶联反应,得到(R)-(+)-2,2’-双[二(3,5-二甲苯基)膦]-1,1’-联萘。通过考察各步的反应条件,得出最佳的工艺条件,(R)-(+)-2,2’-双[二(3,5-二甲苯基)膦]-1,1’-联萘的收率可达67%,e.e.值为99.2%。     

Biodegradable polymers based on renewable resources. IV. Enzymatic degradation of polyesters composed of 1,4:3.6‐dianhydro‐D‐glucitol and aliphatic dicarboxylic acid moieties

Enzymatic degradation of a series of polyesters prepared from 1,4:3.6‐dianhydro‐D ‐glucitol (1) and aliphatic dicarboxylic acids of the methylene chain length ranging from 2 to 10 were examined using seven different enzymes. Enzymatic degradability of these polyesters as estimated by water‐soluble total organic carbon (TOC) measurement is dependent on the methylene chain length (m) of the dicarboxylic acid component for most of the enzymes examined. The most remarkable substrate specificity was observed for Rhizopus delemar lipase, which degraded polyester derived from 1 and suberic acid (m = 6) most readily. In contrast, degradation by Porcine liver esterase was nearly independent of the structure of the polyesters. Enzymatic degradability of the polyesters based on three isomeric 1,4:3.6‐dianhydrohexitols and sebacic acid was found to decrease in the order of 1, 1,4:3.6‐dianhydro‐D ‐mannitol (2), and 1,4:3.6‐dianhydro‐L ‐iditol (3). Structural analysis of water‐soluble degradation products formed during the enzymatic hydrolysis of polyester 5g derived from 1 and sebacic acid has shown that the preferential ester cleavage occurs at the O(5) position of 1,4:3.6‐dianhydro‐D ‐glucitol moiety in the polymer chain by enzymes including Porcine pancreas lipase, Rhizopus delemar lipase, and Pseudomonas sp. lipase. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 338–346, 2000     

Biodegradable polymers based on renewable resources VIII. Environmental and enzymatic degradability of copolycarbonates containing 1,4 : 3,6‐dianhydrohexitols

Environmental and enzymatic degradations were investigated on a series of copolycarbonates consisting of equimolar amounts of 1,4 : 3,6‐dianhydrohexitols (1,4 : 3,6‐dianhydro‐D ‐glucitol (1a) and 1,4 : 3,6‐dianhydro‐D ‐mannitol (1b)) and alkylene diols (1,4‐butanediol, 1,6‐hexanediol, 1,8‐octanediol, and 1,10‐decanediol) or oligo(ethylene glycol)s (di‐, tri‐, and tetraethylene glycols). Fourteen different copolycarbonates with number average molecular weights in the range of 1.1–4.2 × 10⁴ were prepared by solution polycondensation as described in our previous article. Biodegradability of the copolycarbonates was assessed by soil burial degradation tests in composted soil at 27 °C and by enzymatic degradation tests in a phosphate buffer solution at 37 °C. In general, biodegradability of the copolycarbonates increased with increasing chain lengths of the methylene groups of alkylene diols or of the oxyethylene groups of the oligo(ethylene glycol)s. SEM observations of the film surfaces of polymers recovered from soil burial indicated that the copolycarbonates were degraded by microorganisms in soil. In enzymatic degradation, the copolycarbonates containing alkylene diol components showed high degradability with Pseudomonas sp. lipase, whereas the copolycarbonates containing oligo(ethylene glycol) components were not degraded at all. The enzymatic degradability of the copolycarbonates is discussed with reference to the geometrical structure around the carbonate linkages and the microstructure and hydrophobicity of the polymer chains. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1679–1687, 2005     

Biodegradable polymers based on renewable resources. VI. Synthesis and biodegradability of poly(ester carbonate)s containing 1,4:3,6‐dianhydro‐D‐glucitol and sebacic acid units

Poly(ester carbonate)s with different compositions were synthesized by bulk polycondensation of 1,4:3,6‐dianhydro‐D ‐glucitol with diphenyl sebacate and diphenyl carbonate in the presence of zinc acetate as a catalyst. Most of the poly(ester carbonate)s as well as the corresponding polycarbonate were amorphous, except the poly(ester carbonate) with a small carbonate content and the corresponding polyester, which are semicrystalline. All these poly(ester carbonate)s are soluble in chloroform, pyridine, dimethylformamide, dimethyl sulfoxide, and N,N‐dimethylacetamide. Soil burial degradation tests, biochemical oxygen demand (BOD) measurements in an activated sludge, and enzymatic degradation tests indicated that these poly(ester carbonate)s are potentially biodegradable. The biodegradability was found to be maximum for the poly(ester carbonate)s with carbonate contents of 10–20 mol % and to decrease markedly for the poly(ester carbonate)s with the carbonate content above 50 mol %. The biodegradability of the poly(ester carbonate)s is discussed in terms of the crystallinity, glass transition temperature, and surface hydrophobicity of the polymer films. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 872–880, 2002     

Biodegradable polymers based on renewable resources. V. Synthesis and biodegradation behavior of poly(ester amide)s composed of 1,4:3,6‐dianhydro‐D‐glucitol, α‐amino acid,and aliphatic dicarboxylic acid units

A series of poly(ester amide)s were synthesized by solution polycondensations of various combinations of p‐toluenesulfonic acid salts of O,O′‐bis(α‐aminoacyl)‐1,4:3,6‐dianhydro‐D ‐glucitol and bis(p‐nitrophenyl) esters of aliphatic dicarboxylic acids with the methylene chain lengths of 4–10. The p‐toluenesulfonic acid salts were obtained by the reactions of 1,4:3,6‐dianhydro‐D ‐glucitol with alanine, glycine, and glycylglycine, respectively, in the presence of p‐toluenesulfonic acid. The polycondensations were carried out in N‐methylpyrrolidone at 40°C in the presence of triethylamine, giving poly(ester amide)s having number‐average molecular weights up to 3.8 × 10⁴. Their structures were confirmed by FTIR, ¹H‐NMR, and ¹³C‐NMR spectroscopy. Most of these poly(ester amide)s are amorphous, except those containing sebacic acid and glycine or glycylglycine units, which are semicrystalline. All these poly(ester amide)s are soluble in a variety of polar solvents such as dimethyl sulfoxide, N,N‐dimethylformamide, 2,2,2‐trifluoroethanol, m‐cresol, pyridine, and trifluoroacetic acid. Soil burial degradation tests, BOD measurements in an activated sludge, and enzymatic degradation tests using Porcine pancreas lipase and papain indicated that these poly(ester amide)s are biodegradable, and that their biodegradability markedly depends on the molecular structure. The poly(ester amide)s were, in general, degraded more slowly than the corresponding polyesters having the same aliphatic dicarboxylic acid units, both in composted soil and in an activated sludge. In the enzymatic degradation, some poly(ester amide)s containing dicarboxylic acid components with shorter methylene chain lengths were degraded more readily than the corresponding polyesters with Porcine pancreas lipase, whereas most of the poly(ester amide)s were degraded more rapidly than the corresponding polyesters with papain. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2721–2734, 2001     

Novel 1,4‐diketo‐3,6‐diphenyl pyrrolo[3,4‐c]pyrrole (DPP)‐based copolymers with large Stokes shift

Two novel alternating π‐conjugated copolymers, named PDPPDOPV and PDPPDOPE, constituted of 1,4‐diketo‐3,6‐diphenyl pyrrolo[3,4‐c]pyrrole (DPP) with 2,5‐dioctyloxy‐1,4‐phenylenevinylene (DOPV) or 2,5‐dioctyloxy‐1,4‐phenyleneethynylene (DOPE), respectively, were synthesized and characterized by UV‐vis, FT‐IR, and photoluminescence spectroscopy. They are dark red solid readily soluble in various common organic solvents including THF and chloroform. The UV‐vis absorption spectra of the polymers show strong absorption bands, which correspond to the π‐π* transition of π‐conjugated segments. Photoluminescence (PL) spectra show that both polymer films and solution have large Stokes shifts. From their fluorescence behavior, Stokes shifts of 173 nm and 199 nm are derived for the films of PDPPDOPV and PDPPDOPE, respectively, which are the largest two values ever reported for DPP‐containing polymers. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Carbohydrate‐based poly(ester‐urethane)s: A comparative study regarding cyclic alditols extenders and polymerization procedures

A set of segmented poly(ester‐urethane)s were prepared from diisocyanates HDI or MDI and using 1,4‐butanediol and D ‐glucose‐derived cyclic diols (1,4 : 3,6‐dianhydro‐D ‐glucitol (isosorbide) or 2,4;3,5‐di‐O‐methylidene‐D ‐glucitol (gludioxol) or mixtures of them) as extenders. Hydroxyl end‐capped polycaprolactone with a molecular weight of 3000 g·mol^?1 was used as soft segment. Two polymerization methods, in solution and in bulk, were applied for the synthesis of these poly(ester‐urethane)s. The influence of the preparation procedure and composition in cyclic extender on synthesis results, structure, and properties of the novel poly(ester‐urethane)s was comparatively evaluated and discussed. The effect of replacement of 1,4‐butanediol by isosorbide or gludioxol on hydrodegradability was also assessed; the hydrolysis rate increased noticeably with the presence of glucitol derived units, although degradation of the polymers took place essentially by hydrolysis of the polyester soft segment. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Tetrazine Explosives

The synthesis and properties of various 1,2,4,5‐tetrazine explosives and energetic materials are described. These are the nitrate and perchlorate salts of 3,6‐diguanidino‐1,2,4,5‐tetrazine, the nitrate and perchlorate salts of 3,6‐diguanidino‐1,2,4,5‐tetrazine‐1,4‐di‐N‐oxide, 3,6‐bis(1H‐1,2,3,4‐tetrazol‐5‐ylamino)‐1,2,4,5‐tetrazine and its 1,4‐di‐N‐oxide derivative, 3,3′‐azobis(6‐amino‐1,2,4,5‐tetrazine) and its oxidation products.     

Synthese und Reaktionen carbocyclischer Acyl-keten-S,S-acetale

Synthesis and Reactions of Carbocyclic Acyl-ketene-S,S-acetales Cyclohexanone, tetralone(1) and indanone(1) react with CS₂ in the presence of bases and after methylation to 2-[bis(methylthio)-methyliden]-cyclohexanones 1,4 -tetralones(1) 2,5 and -indanones(1) 3,6 . In some cases thiophenes 8 and 9 are formed. The dimethyl-S,S-acetales 1, 2a and 3a react with mono or dinucleophiles to S,N- or N,N-acetales, with hydrazines to indazolone 22 or the pyrazole 23 . Oxidation with H₂O₂ yield disulfones 25 and 27 . The structure of products are determined by ir- and ¹H-n.m.r.-spectroscopy.     

Direct (hetero)arylation polymerization for the synthesis of donor–acceptor conjugated polymers based on N‐benzoyldithieno [3,2‐b:2′,3′‐d]pyrrole and diketopyrrolopyrrole toward organic photovoltaic cell application

In this research, new donor–acceptor (D‐A) photovoltaic polymers were synthesized from dithieno[3,2‐b:2′,3′‐d]pyrrole electron donor derivatives, including N‐benzoyldithieno[3,2‐b:2′,3′‐d]pyrrole and N‐(4‐hexylbenzoyl)dithieno[3,2‐b:2′,3′‐d]pyrrole, in combination with the electron deficient unit 2,5‐bis(2‐ethylhexyl)‐3,6‐di(thiophen‐2‐yl)‐2,5‐dihydropyrrolo[3,4‐c]pyrrole‐1,4‐dione via direct (hetero)arylation polymerization. The D‐A conjugated polymers obtained were characterized via ¹H NMR, gel permeation chromatography, Fourier transform infrared spectroscopy, DSC, XRD, photoluminescence and UV–visible methods. In addition, these D‐A polymers were used as activated layers in bilayer and bulk heterojunction structures for the fabrication of organic photovoltaic cells. © 2019 Society of Chemical Industry     

Development of Diphenylamine‐Linked Bis(imidazoline) Ligands and Their Application in Asymmetric Friedel–Crafts Alkylation of Indole Derivatives with Nitroalkenes

The new diphenylamine‐linked bis(imidazoline) ligands were prepared through Kelly‐You’s imidazoline formation procedure mediated by Hendrickson’s reagent in good yields. The novel ligands were tested in the asymmetric Friedel–Crafts alkylation of indole derivatives with nitroalkenes. In most cases, good yields (up to 97%) and excellent enantioselectivities (up to 98%) can be achieved. The optimized bis(imidazoline) ligand with trans‐diphenyl substitution on the imidazoline ring gave better enantioselectivity than the corresponding bis(oxazoline) ligand.