3-N-乙酰基-2-取代芳基-5-[5′-甲基-异(口恶)唑-3′]-Δ3-1,3,4-(口恶)唑啉类化合物的合成

由相应的酯(1)肼解制得5-甲基-异(口恶)唑-3-甲酰肼(2),后者与醛缩合得到酰腙(3a～3h),3a～3h再进一步与乙酸酐环合,以良好的收率合成出了3-N-乙酰基-2-取代芳基-5-[5′-甲基-异(口恶)唑-3′]-Δ3-1,3,4-(口恶)唑啉衍生物(4a～4h). 以上化合物的结构均经过1H NMR、MS和元素分析的确证.     

手性芳基膦-噁唑啉的简便合成

膦-噁唑啉化合物作为一类“优势配体”,自发现以来就引起化学家们的广泛关注。 现有合成方法存在路线长、收率低、分离困难等问题。 本研究发展了一种合成手性芳基膦-噁唑啉(PHOX)的简单高效方法。 在1-羟基苯并三唑(HOBt)、1-(3-二甲氨基丙基)-3-乙基碳二亚胺盐酸盐(EDCI)作用下,2-(二苯基膦基)苯甲酸与多种光学纯的氨基醇发生缩合反应,高收率获得酰胺基醇类化合物;之后酰胺基醇经三苯基膦/三乙胺/四氯化碳体系处理完成噁唑啉环的构建,以64%86%的总收率得到膦-噁唑啉化合物。 随后,合成的化合物(S)-t-BuPHOX被应用于钯催化β-酮酯的脱羧Tsuji烯丙基化反应,得到了80%的收率和84%的ee值。 该新方法具有原料易得、条件温和、收率高等优点。     

α-氰基肉桂酸乙酯/酰胺/N-溴代丁二酰亚胺三组分合成2-噁唑啉

以α-氰基肉桂酸乙酯衍生物、酰胺和N-溴代丁二酰亚胺(NBS)为原料,在无水碳酸钠促进下,以N,N-二甲基甲酸胺(DMF)为溶剂,室温下建立了三组分合成2-噁唑啉的新体系.在优化条件下,丙酰胺、丙烯酰胺、异丁酰胺和戊酰胺均能与不同结构的α-氰基肉桂酸乙酯衍生物反应,高收率地生成相应的2-噁唑啉(最高收率可达94%),说明该反应具有广泛的适应性.合成了39个新化合物,其结构均由核磁共振氢谱、碳谱和高分辨质谱确证.根据实验结果,提出了该反应的可能机理,该机理有力地支持了形成2-噁唑啉时的区域选择性.     

由α-氰基肉桂酸乙酯/N-溴代苯甲酰胺合成2-噁唑啉衍生物

作为重要的杂环化合物,合成新的2-噁唑啉衍生物以及发展其新的合成方法具有重要意义,为此以α-氰基肉桂酸乙酯衍生物为底物,以N-溴苯甲酰胺为反应试剂,在无水碳酸钠(相对于底物3为110%摩尔分数)促进下,在丙酮溶剂中,室温下,建立了合成相应2-噁唑啉衍生物的新方法,共合成了11个新化合物,其结构由核磁共振波谱仪(~1H NMR,~(13)C NMR)和高分辨质谱(HRMS)确认。结果显示,各种α-氰基肉桂酸乙酯衍生物(3a~3k)可被顺利的转化成相应的2-噁唑啉衍生物(5a~5k)。在室温下,丙酮作溶剂,以Na_2CO_3为促进剂时,相应产物的最高收率可达90%。不仅α-氰基肉桂酸乙酯衍生物(3)可被用作该反应的底物,而且α-乙氧甲酰基肉桂酸乙酯(6)也适用于该反应。实验结果还证明,除了N-溴代苯甲酰胺外,N-溴代对硝基苯甲酰胺(8)及N-溴代乙酰胺(9)也适用该反应,证明该方法具有广泛的适应性。根据实验结果,提出了可能的反应机理,该机理支持了形成2-噁唑啉衍生物的区域选择性。     

4,7-二苯基-1,10-菲啰啉的合成研究

以4-苯基-8-硝基喹啉为起始原料,经还原得到4-苯基-8-氨基喹啉,再以I2/KI为氧化剂,在乙酸和盐酸的存在下,用Skraup法合成了4,7-二苯基-1,10-菲啰啉.化合物结构经IR和1H NMR得到了证实.实验研究得到了最佳的合成条件为:n(3-氯苯丙酮)∶n(4-苯基-8-氨基喹啉)=1.5∶1,I2/KI用量为8%,反应温度120℃,反应时间2.5 h.产品收率可达82%.     

一锅法合成2，4，6-三氯喹唑啉和6-硝基-2，4-二氯喹唑啉

在五氯化磷的存在下,2-氨基-5-氯苯甲酸(1a)或2-氨基-5-硝基苯甲酸(1b)与尿素缩合,一锅法合成了2,4,6-三氯喹唑啉(2a)或6-硝基-2,4-二氯喹唑啉(2b),其结构经1H NMR和ESI-MS表征.合成2a的最佳反应条件为:1a 2.5 mmol,n(1a):n(PCl5):n(尿素)=1.0:6.0:2.2,回流反应1 h,收率41%.     

1-氮杂-2,8-二氧杂二环[3.3.0]-辛烷类化合物合成的新方法

以苯基-3,5-二(甲氧基羰基)-2-异(口恶)唑啉-N-氧化物为偶极体,丙烯酸乙酯为亲偶极体,通过[3+2]环加成反应,简便地合成了含有多官能团的1-氮杂-2,8-二氧杂二环[3.3.0]-辛烷类化合物。该反应条件温和,产率较高(50%～93%).化合物的结构经元素分析,¹H NMR,¹³C NMR,IR和MS确认和表证,并对其波谱性质进行了讨论。     

(S)-3-(3,4-二甲氧基苯基)-2-甲基丙氨酸衍生的手性咪唑啉酮催化剂合成新方法

以(S)-3-(3,4-二甲氧基苯基)-2-甲基丙氨酸盐酸盐为原料,针对其合成咪唑啉酮催化剂过程中反应条件苛刻和反应时间长等问题,重新设计了一条合成路线,并考察了温度、原料摩尔比和反应时间等对合成收率的影响。新合成路线中,合成关键中间体(S)-3-(3,4-二甲氧基苯基)-2-甲基丙氨酸甲酰胺7的反应时间由9 d缩短至7 h,不需剧毒的NaCN催化,收率达到98%。     

1,8-二氮杂二环十一碳-7-烯(DBU)立体选择性催化合成噁唑啉-2-(硫)酮衍生物

以1,8-二氮杂二环十一碳-7-烯(DBU)为催化剂,在无其它金属催化条件下,炔丙醇与异氰酸酯(或硫氰酸酯)进行亲核加成/环化反应,合成了一系列多取代的噁唑烷-2-(硫)酮衍生物,收率为75%~95%.该反应经5-exo-dig环化机制,高度立体选择性地得到Z-式芳亚甲基取代产物,为噁唑啉酮的骨架合成提供了简单快速的合成方法.     

新型手性膦噁唑啉铱络合物的合成及其在氢化反应中的应用

在鹰爪碱诱导下,2-氯甲基-4,4-二甲基噁唑啉与叔丁基苯基膦硼烷经络合反应,以43%的收率合成了光学纯度大于99%,手性中心在P上的新型手性噁唑啉氮膦配体(3); 3和铱配合物(［Ir(cod)Cl］₂)经络合反应以55%的收率制得两个新型手性膦噁唑啉铱络合物催化剂(1和2),其结构经¹H NMR, ¹³C NMR, ³¹P NMR和元素分析表征。考察了1和2对烯烃的不对称氢化反应的催化性能。结果表明：1具有较好的催化能力,收率＞92%,但催化剂的手性诱导能力较差(ee≤36%)。     

耐热性星形甲基丙烯酸甲酯共聚物的合成

195 6年 ,Swarzc等 [1,2 ] 报道了一种没有链转移和链终止的阴离子聚合技术 ,提出了“活性”聚合的概念 . 1 995年王锦山等 [3]发现和提出原子转移自由基聚合 ( ATRP)以来 ,活性自由基聚合就成了高分子合成领域的研究热点 ,并合成出各类指定结构的聚合物 [4～ 12 ] .具有环状结构的 N -环己基马来酰亚胺 ( NCMI)被广泛地用于与甲基丙烯酸甲酯 ( MMA)自由基共聚合制备耐热性有机透明材料 [13,14 ] ,但NCMI的引入将降低聚合物的加工流动性 ,若能利用多官能团引发剂如四溴甲基苯实现含 NCMI单体结构的可控 ATRP共聚合 ,合成出星形耐…     

Synthesis and polymerization reactions of cyclic imino ethers. I. Ring‐opening homopolyaddition of AB‐type hydroxyphenyl‐substituted 2‐oxazolines

Homopolyaddition reactions of AB‐type monomers containing a 2‐oxazoline and a phenol group in different positions of the phenyl ring, namely, 2‐(4‐hydroxyphenyl)‐2‐oxazoline, 2‐(3‐hydroxyphenyl)‐2‐oxazoline, 2‐(2‐hydroxyphenyl)‐2‐oxazoline, and 2‐(4‐hydroxyphenyl)‐4,4‐dimethyl‐2‐oxazoline, were studied. Except for 2‐(4‐hydroxyphenyl)‐4,4‐dimethyl‐2‐oxazoline, the reaction carried out in bulk or a solution of highly boiling solvents resulted in the formation of poly(ether amide)s with molecular weights in the range of 10³ to 10⁴ as measured by vapor pressure osmometry and gel permeation chromatography. A mechanism of the growth reaction, including a nucleophilic attack of a phenol group to a 2‐oxazoline ring in the 5‐position, was suggested. The polymerization was accompanied by a side reaction of the amido groups formed by the primary reaction of the 2‐oxazoline ring. This led to branching of the main chain. The thermal properties of the prepared polymers were evaluated. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 343–355, 2006     

Chiral and water‐soluble poly(2‐oxazoline)s

We describe the synthesis and characterization of the first water‐soluble and chiral poly(2,4‐disubstituted‐2‐oxazoline)s. While poly(2,4‐dimethyl‐2‐oxazoline)s are water soluble up to 100 °C, aqueous solutions of poly(2‐ethyl‐4‐methly‐2‐oxazoline) exhibit a lower critical solution temperature. This is discussed in context with its constitutional isomers poly(2‐oxazoline)s and poly(2‐oxazine)s. Circular dichroism spectroscopy revealed strong Cotton effects, which are also responsive to temperature in aqueous solution. It is therefore hypothesized that structures, comparable to polyproline helices, are formed in aqueous solution. In contrast to polyproline, poly(2,4‐disubstituted‐2‐oxazoline)s are highly water soluble and therefore represent very interesting pseudo‐polypeptides that may be useful to develop responsive biomimetic biomaterials. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013     

Microwave Accelerated Polymerization of 2‐Phenyl‐2‐oxazoline

Summary: We studied the cationic ring‐opening polymerization of 2‐phenyl‐2‐oxazoline under microwave irradiation. A comparison with thermal heating shows a great enhancement in the reaction rates while the living character of the polymerization is conserved. The polymerizations were performed at the temperature of boiling butyronitrile (123 °C). The polymerization of 2‐phenyl‐2‐oxazoline under microwave conditions, described herein for the first time, is shown to be a rapid and environmentally friendly alternative to the classical methods.

Schematic of the activation of the reactive site by microwave irradiation.     

Comparative studies on miscibility and phase behavior of linear and star poly(2‐methyl‐2‐oxazoline) blends with poly(vinylidene fluoride)

The comparative studies on the miscibility and phase behavior between the blends of linear and star‐shaped poly(2‐methyl‐2‐oxazoline) with poly(vinylidene fluoride) (PVDF) were carried out in this work. The linear poly(2‐methyl‐2‐oxazoline) was synthesized by the ring opening polymerization of 2‐methyl‐2‐oxazoline in the presence of methyl p‐toluenesulfonate (MeOTs) whereas the star‐shaped poly(2‐methyl‐2‐oxazoline) was synthesized with octa(3‐iodopropyl) polyhedral oligomeric silsesquioxane [(IC₃H₆)₈Si₈O₁₂, OipPOSS] as an octafunctional initiator. The polymers with different topological structures were characterized by means of Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy. It is found that the star‐shaped poly(2‐methyl‐2‐oxazoline) was miscible with poly(vinylidene fluoride) (PVDF), which was evidenced by single glass‐transition temperature behavior and the equilibrium melting‐point depression. Nonetheless, the blends of linear poly(2‐methyl‐2‐oxazoline) with PVDF were phase‐separated. The difference in miscibility was ascribed to the topological effect of PMOx macromolecules on the miscibility. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 942–952, 2006     

CuOx/TiO2光催化水蒸气还原CO2

以商品TiO2-P25为原料,通过浸渍法负载一定量过渡金属Cu,得到一系列不同含量的CuOx/TiO2光催化剂。利用X射线衍射（XRD）,X－射线光电子能谱（XPS）,BET,高分辨率透射镜（HRTEM）,X射线荧光光谱（XRF）和光致发光光谱（PL）等方法对催化剂进行了详细表征,在自建的光催化反应器中评价了气态水光催化还原CO2反应的活性和CH4收率。结果表明负载CuOx后的TiO2纳米材料光催化性能显著提高,其中1%CuOx/TiO2样品紫外光照72 h后,CH4生成量达到了24.86 µmol•gTi-1。同时,CuOx负载量、反应温度、反应时间等因素对CH4收率均有显著影响。     

Tuning of Thermoresponsivity of a Poly(2‐alkyl‐2‐oxazoline) Block Copolymer by Interaction with Surface‐Active and Chaotropic Metallacarborane Anion

Thermoresponsive nanoparticles based on the interaction of metallacarboranes, bulky chaotropic and surface‐active anions, and poly(2‐alkyl‐2‐oxazoline) block copolymers were prepared. Recently, the great potential of metallacarboranes have been recognized in biomedicine and many delivery nanosystems have been proposed. However, none of them are thermoresponsive. Therefore, a thermoresponsive block copolymer, poly(2‐methyl‐2‐oxazoline)‐block‐poly(2‐n‐propyl‐2‐oxazoline) (PMeOx–PPrOx), was synthesized to encapsulate metallacarboranes. Light scattering, NMR spectroscopy, isothermal titration calorimetry, and cryogenic TEM were used to characterize all solutions of the formed nanoparticles. The cloud‐point temperature (T_CP) of the block copolymer was observed at 30 °C and polymeric micelles formed above this temperature. Cobalt bis(dicarbollide) anion (COSAN) interacts with both polymeric segments. Depending on the COSAN concentration, this affinity influenced the phase transition of the thermoresponsive PPrOx block. The T_CP shifted to lower values at a lower COSAN content. At higher COSAN concentrations, the hybrid nanoparticles are fragmented into relatively small pieces. This system is also thermoresponsive, whereby an increase in temperature leads to higher polymer mobility and COSAN release.     

Synthesis of new amphiphilic and lypophilic polymer networks containing 2‐methyl‐ and 2‐nonyl‐2‐oxazoline by the macroinitiator method

New amphiphilic and lypophilic polymer networks were obtained by the copolymerization of 2‐methyl‐2‐oxazoline (MeOXA), and/or 2‐nonyl‐2‐oxazoline (NoOXA) and 2,2′‐tetramethylenebis(2‐oxazoline) (BisOXA), respectively, initiating the copolymerization by random copolymers of chloromethylstyrene and methyl methacrylate or of chloromethylstyrene and styrene (macroinitiator method). Potassium iodide was used as an activator agent and the reaction was carried out in benzonitrile at 110 °C. In general, the polymer gels were obtained with a yield of 62 to 88%. The networks were characterized by high‐resolution magic angle spinning (HRMAS) NMR spectroscopy and by its absorption of polar and nonpolar solvents. In the case of amphiphilic polymer networks, the absorption of solvents depends on the molar ratio of 2‐methyl‐ to 2‐nonyl‐2‐oxazoline inside the polymer network favoring the absorption of polar solvents with a higher content of 2‐methyl‐2‐oxazoline. These gels showed a maximal swelling degree of 13 mL of water, 20 mL of methanol, and 13 mL of chloroform, respectively, per g of polymer. The lypophilic polymer networks containing only 2‐nonyl‐2‐oxazoline showed a maximal swelling degree of 8 mL of toluene, 14 mL of chloroform, and 2 mL of methanol, respectively, per g of the lypophilic network. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 122–128, 2005     

Uni‐molecular nanoparticles of poly(2‐oxazoline) showing tunable thermoresponsive behaviors

Herein, cylindrical molecular bottlebrushes grafted with poly(2‐oxazoline) (POx) as a shaped tunable uni‐molecular nanoparticle were synthesized via the grafting‐onto approach. First, poly(glycidyl methacrylate) (PGMA) backbones with azide pendant units were prepared via reversible addition fragmentation transfer (RAFT) polymerization followed by post‐modification. The degree of polymerization (DP) of the backbones was tuned in a range from 20 to 800. Alkynyl‐terminated POx side chains were synthesized by living cationic ring opening polymerization (LCROP) of 2‐ethyl‐2‐oxazoline (EtOx) and 2‐methyl‐2‐oxazoline (MeOx), respectively. The DP of side chains was varied between 20 and 100. Then, the copper‐catalyzed azide‐alkynyl cycloaddition (CuAAC) click chemistry was conducted with a feed ratio of [alkynyl]:[azide] = 1.2:1 to yield a series of brushes. Depending on the DP of side chains, the grafting density ranged between 47 and 85%. The resulting brushlike nanoparticles exhibited shapes of sphere, rod and worm. Aqueous solutions of PEtOx brushes demonstrated a thermoresponsive behavior as a function of the length of backbones and side chains. Surprisingly, it was found that the lower critical solution temperature of PEtOx brushes increased with a length increase of backbones. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56, 174–183     

Aminophosphine–oxazoline and phosphoramidite–oxazoline ligands and their application in asymmetric catalysis

The synthesis of a novel series of aminophosphine–oxazoline and phosphoramidite–oxazoline is described. The efficacy of these aminophosphine–oxazoline ligands was investigated in the palladium catalysed asymmetric allylic alkylation of 1,3-diphenylprop-2-enyl acetate leading to a maximum of 38% ee at 64% conversion. Phosphoramidite–oxazoline ligands, however, gave ees of up to 87% at 71% conversion in the same reaction and also proved to be effective in the palladium catalysed asymmetric Suzuki coupling between 2-methylnaphthylboronic acid and 1-bromonaphthalene, leading to a maximum of 46% ee in 54% isolated yield at room temperature.