GENERAL APPROACH TO THE SYNTHESIS OF SYMMETRICAL 1,3,2-DIAZAPHOSPHOCANES

Abstract

Synthesis of eight-membered phosphorus-nitrogen heterocycles has been performed by phosphocyclization of the corresponding diamines using different derivatives of phos horous acid. The structures of diazaphosphocanes were supported by elemental analysis; ¹H, ¹³C, and ³¹PNMR spectroscopy; and x-ray diffraction analysis.     

二氢茉莉酮酸甲酯的简便合成方法

本文报道二氢茉莉酮酸甲酯的简便合成方法。先由丁二酸和庚酰氯反应得到2-戊基-1,3-环戊二酮(1),再用甲醇醚化1,可得到2-戊基-3-甲氧基-环戊-2-烯酮(2)。2与丙二酸二甲酯反应生成(2-戊基-3-酮-1-环戊烯-)基乙酸甲酮(3)。最后,催化氢化3,便可得到二氢茉莉酮酸甲酯(4)。     

淀粉聚醚多元醇的合成研究

近年来由于石油价格的上涨,严重地限制了聚氨酯工业的发展。因此用价廉易得的再生资源淀粉代替部分化工产品合成聚醚多元醇,减少对石油产品的依赖性,降低成本,对发展聚氨酯工业和给淀粉寻找新的出路,具有十分重要的现实意义和新的战略意义。     

含有二个聚醚软链段的聚醚聚酯嵌段共聚物的合成及其血液相容性的研究

 本文报道了一类新的具有二种聚醚软链段(PTMGT和PEGT)和一种聚酯硬链段(PET)的混合聚醚-聚酯嵌段共聚物(MPEE)的合成和它的血液相容性,并与具有相同软、硬链段比及相同软链段组成比(PTMGT/PEGT)的二种聚醚聚酯嵌段共聚物(PTMGT-PET和PEGT-PET)的共混物(BPEE)的性质进行了比较,结果表明:(1)聚醚聚酯嵌段共聚物的血液相容性可以通过引入亲水性好的PEGT组分而得到提高;(2)在多数的组成比下,共聚型的MPEE具有比共混型的BPEE优良的血液相容性;(3)特定的组成比:PTMGT/PEGT=60/40(mol),共混型的BPEE:(60/40)呈现最好的血液相容性以及最佳的力学性质。研究中发现材料的微相分离结构同血液相容性有关,细微的相分离结构可导致优良的血液相容性。     

含有二个聚醚软链段的聚醚聚酯嵌段共聚物的合成及其血液相容性的研究

本文报道了一类新的具有二种聚醚软链段(PTMGT和PEGT)和一种聚酯硬链段(PET)的混合聚醚-聚酯嵌段共聚物(MPEE)的合成和它的血液相容性,并与具有相同软、硬链段比及相同软链段组成比(PTMGT/PEGT)的二种聚醚聚酯嵌段共聚物(PTMGT-PET和PEGT-PET)的共混物(BPEE)的性质进行了比较,结果表明:(1)聚醚聚酯嵌段共聚物的血液相容性可以通过引入亲水性好的PEGT组分而得到提高;(2)在多数的组成比下,共聚型的MPEE具有比共混型的BPEE优良的血液相容性;(3)特定的组成比:PTMGT/PEGT=60/40(mol),共混型的BPEE:(60/40)呈现最好的血液相容性以及最佳的力学性质。研究中发现材料的微相分离结构同血液相容性有关,细微的相分离结构可导致优良的血液相容性。     

AN APPROACH TO OLIGONUCLEOTIDE SYNTHESIS BY THE PHOSPHOTRIESTER METHOD

Abstract

A systematic approach to the chemical synthesis of oligoribo- and oligodeoxyribo-nucleotides is described. Synthesis in both series of oligonucleotides has been tackled as a two-stage problem. The first stage, which is concerned with the preparation of correctly-orientated, suitably-protected nucleoside building blocks, has been completed. The second stage, which is concerned with the development of an effective phosphorylation procedure for linking the building blocks together, is presently being investigated. From the results obtained so far, it is apparent that the phosphotriester approach to the synthesis of oligonucleotides, especially with phenyl (and other aryl) protecting groups, is superior to approaches which involve unprotected internucleotide linkages during synthesis.     

UNIVERSAL APPROACH TO THE SYNTHESIS OF JUVENOID HYDROPRENE AND METHOPRENE FROM 4-METHYLTETRAHYDROPYRAN

A universal approach to the synthesis of juvenoid hydroprene and methoprene was developed on the basis of monoalkylation of acetoacetate by 1-acetoxy-5-bromo-3-methylpentane, the product of acidic decyclization of 4-methyltetrahydropyran.     

A MOLECULAR APPROACH TO THE SYNTHESIS OF NOVEL POLYIMIDES*

In the past ten years there has been a flurry of activity in the synthesis of new specialty polymers,largely as a result of the increased need for high technology materials. Interest is mainly shown in two distinctcategories of polymers: a) polymers which are used in very small quantities to fulfill critical needs as a part ofdevice systems, and b) high-performance engineering polymers which significantly extend their mechanicaland thermal properties for structural applications. Polyimides and their unparalleled versatility have capturedthe attention and imagination of scientists and engineers. This article describes some of the recent work doneby the author's group on the rational design at the molecular level and the synthesis of polyimides that haveunusual structures and novel properties.     

磺化聚醚酮酮的合成和表征

研究了以硫酸为磺化剂由聚醚酮酮来合成磺化聚醚酮酮的方法，探讨了硫酸浓度、反应温度、反应时间和聚醚酮酮在硫酸中的浓度等因素对聚醚酮酮的磺化度和离子交换容量的影响，制得了磺化度为１５５ｍｍｏｌ／ｇ、离子交换容量为１５７ｍｍｏｌ／ｇ的磺化聚醚酮酮．用红外光谱表征了其结构，用Ｘ 射线进行了结晶度的分析，用ＤＳＣ进行了热分析     

末端含三甲基硅基树枝状低聚苯的合成与表征

树枝状聚合物是一类结构有序、有特定分子量、末端可带活性官能团的多功能聚合物,其应用研究涉及信息贮存材料、高级催化剂、非线性光学材料、液晶材料、纳米材料、缓释药物载体、传感器材料、污水处理剂、分离膜及流变学改性剂等领域.以含多功能团的低聚苯为中心核,通过过渡金属催化的芳基偶联反应或Diels-Alder环加成反应,经“收敛法”或“发散法”可以制得结构准确、尺寸可控的树枝状聚苯纳米材料;另一方面,由于核心分子结构的多样性,可以设计、合成拓扑形态各异的树枝状聚苯应用于有机发光材料、有机磁性体、碟状液晶、管束状分子通道、分子识别、储氢材料及锂电池等领域,从而丰富其结构与性能关系的研究内容.因此,树枝状聚苯中心核的设计与合成在这类材料的应用研究中显得尤为重要.本工作设计与合成了一类树枝状聚苯的中心核12和13,其分子末端的生长点被三甲基硅基（TMS-）所保护;采用凝胶渗透色谱（GPC）和粉末X射线衍射等分析手段,以及与其母体结构,即末端不含三甲基硅基的模型化合物1,3,5-三（3＇,5＇-二苯基苯基）苯11进行比较,探讨了分子末端的三甲基硅基及其取代位置对树枝状低聚苯的凝胶渗透色谱行为和结晶性的影响.     

PAMAM树状大分子对酮基布洛芬溶解度的影响

以酮洛芬为模型药物,研究聚酰胺-胺(PAMAM)树状大分子对酮洛芬的增溶作用,并探讨其作用机理.采用紫外光谱法测定了G1.0、G1.5、G2.0、G2.5、G3.0、G3.5PAMAM在不同浓度和不同pH时对酮洛芬的增溶量.并运用计算机模拟方法对PAMAM与酮洛芬相互作用的机理进行了探讨.实验结果表明,酮洛芬的溶解度随溶液pH值变化而变化,在pH4.0～6.0范围内,PAMAM树状大分子对酮洛芬的增溶量随着PAMAM的代数、浓度和溶液pH的增加而增大.整代和半代都具有增溶作用.然而,在同一pH条件下,对于具有相同官能团数目的整代和半代,整代增溶效果要高于半代.计算机模拟结果表明PAMAM与酮洛芬主要靠静电作用力结合.增溶机理可能是酮洛芬的羧基与PAMAM的伯胺和叔胺发生静电作用.     

小肽修饰的PAMAM树枝状化合物的生物活性

合成了甘氨酸 (Gly) 天冬氨酸 (Asp)组成的肽链Gly Asp、Gly Asp Gly Asp、Gly Asp (Gly Asp) 2 .分别将天冬氨酸及上述合成的肽链引入到聚酰胺 胺型树枝状化合物 (PAMAM)的表面 .对所得化合物进行了分子模拟 ,结果表明Gly Asp (Gly Asp) 2 肽链在PAMAM表面可形成接近于 β sheet的构象 .由实验得知 ,经Asp、Gly Asp、Gly Asp Gly Asp、Gly Asp (Gly Asp) 2 修饰的PAMAM树枝状化合物对抗坏血酸还原FeⅢ 细胞色素C(cytc)的反应有干扰作用 ,导致该反应速率下降 .这说明所合成的化合物与cytc有较好的结合能力 .特别是Gly Asp (Gly Asp) 2 修饰的PAMAM ,其与cytc的结合常数为 1 6ⅹ 1 0 5.     

等效剂在合成中的应用研究：Ⅵ.合成二氢茉莉酮的新途径

茉莉酮和二氢茉莉酮是一类名贵的香料,此类化合物的合成一直是人们所关注的问题。已有许多报道,其中包括庚醛、1-硝基庚烷与甲基乙烯基酮进行Michael加成和以硝代甘缩酮与庚醛进行硝-醛缩合制得1,4-二酮,再进行分子内缩合为二氢茉莉酮。这些合成方法,有的对反应条件要求较苛刻,不易操作,有的则反应步骤较多,收率低。最近,白俊才等以甲基乙烯基酮和1-己烯为原料,合成了二氢茉莉酮,此法虽然新颖,但氧硼杂环己烷中间体     

嵌有长聚醚软段液晶共聚酯的合成

本文用对苯二甲酰氯、对苯二酚、己二醇及分子量为1000或2000的聚丁二醇醚,经溶液缩聚制备了嵌段聚醚聚酯,其介晶单元含量只为21.2重量％(或37.5mol％)即可在宽的温度范围内呈现明显的液晶性.~1H-NMR谱表明,产物的聚酯段呈嵌段微观序列分布.     

ACCELERATED SYNTHESIS AND RELEASE OF ANGIOTENSIN II IN THE RAT BRAIN DURING ELECTROACUPUNCTURE TOLERANCE

Behaviouzal studies suggested that cerebral angiotensin Ⅱ (AⅡ) plays an important role in the development of tolerance to electroacupuncture (EA) analgesia. Observations made in this study revealed an increase in AⅡ immunoreactivity (AⅡ-it) in both CSF and brain as well as an increase in the cerebral content of AⅠ-ir in rats rendered tolerant to EA. The extracts of brain from rats receiving EA for 1h and 3h were subjected to gel filtration and the elution profile was compared with that of normal brain extract. There was a marked right shift of the AⅡ peak from the large molecule precursor to the small molecule AⅡ-ir.The latter peak showed the same retention time in HPLC system as that of AⅡ. The results suggest that the acceleration of the synthesis and release of AⅡ during s Iong-term EA stimulation might constitute one of the mechanisms for EA tolerance.     

RADICAL CYCLISATION BASED APPROACH TO LIGNANS. SYNTHESIS OF 4-ARYLMETHYLDIHYDROFURAN-2-ONES

Bromoacetalisation of the cinnamyl alcohols 7a–d, obtained from the corresponding benzaldehydes, generated the bromoacetals 10a–d. The 5-exo trig radical cyclisation of the bromoacetals 10a–d followed by one step hydrolysis-oxidation of the resulting cyclic acetals 11a–d furnished the title compounds 6a–d, respectively, well-established intermediates of a variety of lignans.     

用负载双金属催化剂合成聚醚

用PBM催化剂,以环氧丙烷为单体,成功地制备了聚醚。其特点是催化剂用量小,单体转化率高,聚合较稳定,产物分子量高且可以人为调控。聚合物官能度比较确定。     

NEW APPROACHES TO THE SYNTHESIS OF ORGANOPHOSPHORUS COMPOUNDS

Abstract

The past two decades have brought us a snowballing development of organophosphorus chemistry. Indeed organophosphorus compounds have found wide practical application (in agriculture, petroleum industry, as drugs, etc.) and continue to afford promising objects for the study of theoretical matters such as tautomerism, ambiphilicity, ambidenticity, and other problems of organic chemistry. On the other hand, however impressive this progress may be, the search for new methods of synthesis, improving the known methods and forecasting new types of organophosphorus compounds remain as challenging problems as before.     

聚醚环氧化合物的合成及其改性环氧树脂的研究

本文采用原料易得、价廉而分子量较大的聚醚树脂合成相应的聚醚环氧化合物及其胺的预反应物,研究其对环氧树脂的改性效果,用红外光谱、差热分析和透视电镜研究其相结构。     

开环共聚法合成热可逆共价交联聚醚橡胶

以烷基铝为催化剂,双环戊二烯二甲酸双缩水甘油酯为交联单体,与环氧氯丙烷、环氧乙烷、环氧丙烷进行离子型开环共聚,制得了热可逆共价交联的聚醚橡胶．研究了聚合方法、聚合配方和工艺条件对单体转化率、共聚物组成的影响．通过 Ｉ Ｒ 和 Ｄ Ｓ Ｃ 测定及反应溶解性和高温成型实验,证明了共聚物的结构及共价交联的热可逆转化特性．