质体醌类化合物的合成研究

醌环的取代基对醌类化合物进行光合作用的电子传递过程有很大影响. 我们设想若能在保持与醌环上的甲基相近体积的条件下, 将其中一个甲基换成氯原子, 这样, 这类化合物醌环上的电子密度显然会低于质体醌, 从而进一步研究它们在光合作用中的作用, 有助于进一步阐明光合作用机制, 以3-氯-2-甲基苯胺为原料, 经氧化, 自由烷基化反应, 合成了十六个具有不同长侧链结构的质体醌类似物.     

用循环伏安法研究醌亚胺的脱氨反应

用循环伏安法研究了N,N-二乙基对苯二胺,N,N,N′,N′-四乙基对苯二胺,N,N-二乙基氨基酚三类化合物的电化学氧化及其氧化产物的后继化学反应,求算了脱氨反应速率常数,揭示了苯环上甲基取代基和氮原子上不同取代基对脱氨反应的影响。 脱氨反应为OH^-或水进攻醌亚胺的亲核反应。由于甲基的斥电子效应,当苯环上引进甲基取代基时,环上负电荷增大,带正电荷的醌亚胺趋于稳定,水解反应速度减慢。 苯环上引进二个甲基取代基,其相应的苯胺化合物的半波电位下降大约120mV。二乙基对苯二胺的苯环上每引进一个甲基取代基,其氧化产物与彩色成色剂偶合生成的染料的吸收峰向长波方向移动20-30nm。     

聚{吡咯-2,5-二[(对二甲氨基)苯甲烯]}的电化学和原位拉曼光谱

采用电化学循环伏安法（CV）和原位拉曼光谱（in situ Raman）对窄能隙共轭高分子聚{吡咯 2,5 二[(对二甲氨基)苯甲烯]}（PPDMABE）的电化学行为进行了研究.结果表明,在不同pH值NaNO3溶液中, PPDMABE的电化学氧化还原过程中存在吡咯环的氧化态结构与芳式和醌式结构之间的转变.聚合物在氧化态时吡咯环主要以氧化态存在,而还原态以芳式和醌式结构吡咯环为主.PPDMABE在酸性和中性介质中氧化态吡咯环以质子化的状态存在,而在碱性溶液中氧化态吡咯环既有质子化态,又有去质子化态的.在酸性条件下,PPDMABE较易发生氧化还原反应,而在碱性条件还原反应则较难发生.     

含有冠醚及偶氮苯基团的铂基菱形大环化合物的合成

亚硝基苯与对物3和3,5-二溴苯酚发生亲核取代反应得到化合物4,化合物4与4-乙炔基吡啶盐酸盐发生Sonogashira偶联反应得到化合物5。以3,6-二溴-9,10-菲醌为原料,先后经还原反应和亲核取代反应得到化合物7,化合物7与四（三乙基磷）铂反应生成有机金属铂配体8。化合物5和化合物8通过配位驱动自组装方法合成铂基菱形大环化合物1,其结构经核磁、质谱和紫外可见吸收光谱表征。     

环己烷并卟啉的合成及光谱和电化学性质研究

合成了三种在中位上具有不同取代苯基的环己烷并卟啉:5,10,15,20-四(4-甲苯基)环己烷并卟啉,5,10,15,20-四苯基环己烷并卟啉和5,10,15,20-四(4-氯苯基)环己烷并卟啉。利用核磁共振及质谱对它们进行了结构表征,研究了它们在二氯甲烷和吡啶溶剂中的紫外-可见光谱和电化学性质,探讨了卟啉大环周边的取代基和溶剂对化合物的光谱和氧化还原电位的影响,发现β-位上的环己烷取代基对化合物的光谱和电化学性质具有显著的影响。     

焦脱镁叶绿酸-a的C(12)-位非甲基化及其叶绿素类二氢卟吩衍生物的合成

以叶绿素降解产物脱镁叶绿酸-a甲酯为起始原料,利用空气氧化反应在12-位上引进甲酰基,再通过氧化、还原、Grignard、Knoevenagel、Cannizzaro和1,3-偶极环加成等经典反应进行官能团转换,并对五元外接E-环实施结构改造,在C(12)-位上分别建立了能与大环色基形成不同共轭程度的酰基、酯基和取代烃基,完成了一系列未见报道的叶绿素类二氢卟吩衍生物的合成,其化学结构均经UV,IR,1H NMR及元素分析予以证实,同时也讨论了C(12)-位非甲基化对叶绿素类四吡咯大环分子所形成的各种影响.     

有机金属钼催化下的甲基萘氧化反应

本文研究了在液相条件下用有机金属钼作均相催化剂,叔丁基过氧化氢作氧化剂,把甲基萘氧化成甲基萘醌的反应。讨论了溶剂、催化剂、反应温度、氧化剂与甲基萘的配比以及萘环上不同取代基对反应的影响,     

新型二茂铁异噁唑啉衍生物的合成及其电化学性能

二茂铁基α,β-不饱和烯酮与腈氧化物发生1,3-偶极环加成反应合成了7个3-取代苯基-4-苯基-5-二茂铁甲酰基异噁唑啉(4a～4g),产率中等,其结构经1H NMR, IR和MS表征.通过循环伏安曲线研究了4的电化学性能,结果表明,苯环上的取代基对4的氧化还原电位有一定影响.     

金属卟啉的电化学性质与其催化氧化α-蒎烯性能的关系

 采用循环伏安法对一系列四苯基金属卟啉的电化学氧化还原性质进行了研究,考察了四苯基金属卟啉的第一还原电位与其催化氧化α-蒎烯性能的关系. 结果表明,各四苯基金属卟啉催化空气氧化α-蒎烯转化率的大小顺序为 TPPMnⅢCl＞TPPCoⅢCl＞TPPFeⅢCl＞TPPCuⅡ≈TPPNiⅡ≈TPPZnⅡ,除TPPCoⅢCl外,基本与其第一还原电位的大小顺序一致. 随着卟啉环上取代基供电子能力的减弱,各取代基铁卟啉和锰卟啉的第一还原电位E1值均逐渐减小,表现在催化体系中是它们越容易被还原而引发反应,催化氧化α-蒎烯的转化率逐渐升高. 四苯基铁卟啉和锰卟啉的第一还原电位E1与其卟啉环上对位取代基常数σ*之间均有良好的线性关系.     

天然有机化合物的质谱研究 VI: 20-C-未被氧化的-对映-贝壳杉烯化合物的质谱

用EIMS、高分辨及B/E联动扫描技术, 对二十一个20-C-未被氧化的-对映-贝壳杉烯化合物的结构特征进行了研究, 根据它们的结构和质谱行为, 分为三种类型的化合物,B环的7C上有取代基, B环的6C上有取代基, B环的6C和7C同时有取代基, 并讨论裂解过程与A、B、C环上的取代基的影响。     

Reactions of 1,2-diaza-1,3-dienes with thiol derivatives: a versatile construction of nitrogen/sulfur containing heterocycles

The synthesis of substituted 2,3-dihydro-1,4-thiazines, fused cycloalkyl-1,4-thiazines, 1,4-benzothiazines and fused cycloalkyl-1,4-benzothiazines by 1,4-addition of 1,2-aminothiols to 1,2-diaza-1,3-dienes bearing carboxylate, carboxamide, or phosphorylated groups and subsequent internal heterocyclization is described. The reaction of carboxylated 1,2-diaza-1,3-butadienes with 2-(butylamino)ethanethiol affords 1,4-thiazinan-3-ones. The solid-phase reaction of polymer-bound 1,2-diaza-1,3-butadienes with 1,2-aminothiols produces 2,3-dihydro-1,4-thiazines and 1,4-benzothiazines.     

Self-assembled dynamics of silver nanoparticles and self-assembled dynamics of 1,4-benzenedithiol adsorbed on silver nanoparticles: Surface-enhanced Raman scattering study

Self-assembled dynamics of silver nanoparticles and self-assembled dynamics of 1,4-benzenedithiol (1,4-BDT) adsorbed on silver nanoparticles were investigated experimentally with surface-enhanced Raman scattering (SERS) and theoretically with density functional theory (DFT) and finite difference time domain (FDTD) method. The absorption spectroscopy of 1,4-BDT in silver sol at different time intervals was measured, which give the indirect evidence of self-assembled dynamics of silver nanoparticles and self-assembled dynamics of 1,4-benzenedithiol (1,4-BDT) adsorbed on silver nanoparticles. To obtain the direct evidence of self-assembled dynamics of silver nanoparticles and self-assembled dynamics of 1,4-benzenedithiol (1,4-BDT) adsorbed on silver nanoparticles, the SERS of 1,4-BDT were measured experimentally and investigated theoretically. The appearances of S–S stretching band (revealing the formation of multilayers of 1,4-BDT), and strongly enhanced S–C stretching, C–C ring stretching vibrational modes clearly show self-assembled dynamics of 1,4-BDT.     

Reaction of thiosalicylic acid with 1,4-quinones and cyclization of the resulting arylsulfanylbenzoic acids

Thiosalicylic acid reacts with 1,4-benzoquinone to give 2-(1,4-dihydroxyphenylsulfanyl)benzoic acid which undergoes intramolecular cyclization to 1,4-dihydroxythioxanthen-9-one in the presence of dehydrating agents. Cyclization of arylsulfanylbenzoic acids obtained by reaction of thiosalicylic acid with 1,4-naphtho- and anthraquinones leads to 1,4-quinone derivatives, benzo- and naphthothioxanthenetriones.     

Perfluorinated cyclo-tetrakis(phenylene sulfides): synthesis and structure

Perfluoro-cyclo-tetrakis(1,4-phenylene sulfide) has been synthesized by the reaction of tetrafluorobenzene-1,4-dithiol with perfluoro-1,4-bis(phenylthio)benzene. The reaction of tetrafluorobenzene-1,4-dithiol with perfluoro-m-xylene gives a macrocycle with 1,3- and 1,4-arrangement of bridged sulfur atoms.     

Simons electrochemical fluorination of substituted homopiperazines(hexahydro-1,4-diazepines) and piperazines

Simons electrochemical fluorination (ECF) of 1,4-dimethyl-1,4-homopiperazine, methyl 4-ethylhomopiperazin-1-ylacetate and 1,4-bis(methoxycarbonylmethyl)-1,4-homopiperazine was studied. For comparison, ECF of three piperazines with a N-(methoxycarbonylmethyl) group(s) was also studied. ECF of 1,4-dimethyl-1,4-homopiperazine gave a low yield of corresponding perfluoro(1,4-dimethyl-1,4-homopiperazine) together with perfluoro(2,6-diaza-2,6-dimethylheptane) as the major product. Corresponding perfluoro(homopiperazines) with mono- and/or di-(fluorocarbonyldifluoromethyl) groups [CF₂C(O)F] at the 1- and/or 4-position were formed in low yields from methyl 4-ethylhomopiperazin-1-ylacetate and 1,4-bis(methoxycarbonylmethyl)-1,4-homopiperazine, respectively. These new seven-membered perfluoro(1,4-dialkyl-1,4-homopiperazines) were accompanied by the formation of mono- and/or di-basic linear perfluoroacid fluorides resulting from the CC bond scission at the 2- and 3-positions of the ring. From mono- and/or di-N-(methoxycarbonylmethyl)-substituted piperazines, corresponding perfluoropeperazines having the acid fluoride group(s) were formed in low yields.     

Preparation of 2,3- and 2,5-dihydropyrazine 1,4-dioxides from 2-hydroxyamino-2-methylpropanal oxime and some of their properties

3-Hydroxy-2,3-dihydropyrazine 1,4-dioxide derivatives were obtained by condensation of 2-hydroxyamino-2-methylpropanal oxime with glyoxal, diacetyl, and 1,2-cyclohexanedione in water, and 3-methoxy-2,3-dihydropyrazine 1,4-dioxide was obtained by condensation with diacetyl in methanol. 2,5-Dihydropyrazine 1,4-dioxide is formed when 2-hydroxyamino-2-methylpropanal oxime is heated in a solution of acetone and dilute hydrochloridic acid. The reduction of 3-hydroxy- and 3-methoxy-2,3-dihydropyrazine 1,4-dioxides and 2,5-dihydropyrazine 1,4-dioxide leads to 1,4-dihydroxypiperazines, and the bromination of 3-methoxy-2,3-dihydropyrazine 1,4-dioxide gives 5,6-bis(bromomethyl)-3-methoxy-2,3-dihydropyrazine 1,4-dioxide. 1,4-Dihydroxy-2,5-piperazinedione was obtained by oxidation of 2,5-dihydropyrazine 1,4-dioxide.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1414–1418, October, 1983.     

Preparation of dibenzofuran-type amorphous polyetherketone by novel etherification reaction

4-Fluorobenzophenone reacted with potassium carbonate in the presence of silica catalyst in diphenyl sulfone solvent to yield 4,4′-dibenzoyldiphenyl ether. This new etherification reaction was extended to three difluoro aromatic ketones. 4,4′-Bis(4-fluorobenzoyl)diphenyl ether ( I ) reacted with potassium carbonate to yield a crystalline poly(oxy-1,4-phenylene-carbonyl-1,4-phenylene) (PEK) and 4,4′-bis{4-[4-(4-fluorobenzoyl)phenoxy]benzoyl}benzene ( II ) gave a crystalline poly(oxy-1,4-phenylene-carbonyl-1,4-phenylene-oxy-1,4-phenylene-carbonyl-1,4-phenylene-oxy-1,4-phenylene-carbonyl-1,4-phenylene-carbonyl-1,4-phenylene)(PEKEKEKK). 2,8-Bis(4-fluorobenzoyl)dibenzofuran ( III ) or 2,8-bis(4-chlorobenzoyl)dibenzofuran ( IV ) reacted with potassium carbonate to yield a poly(oxy-1,4-phenylene-carbonyl-2,8-dibenzofuran-carbonyl-1,4-phenylene) (PEKBK). The PEKBK was a noval amorphous polymer with the glass transition temperature of 222°C and it showed excellent thermal stability [T. Tanabe and I. Fukawa, Jpn. Pat., Kokai 64–74223 (1989)]. Several amorphous dibenzofuran type polyetherketone copolymers were prepared by coplycondensation of III with 4,4′-difluorobenzophenone ( V ) or 1,4-bis(4-fluorobenzoyl)benzene ( VI ) [T. Tanabe and I. Fukawa, Jpn. Pat., Kokai 1153722 (1989)]. © 1992 John Wiley & Sons, Inc.     

Synthesis of New Substituted 2,3-Dihydro-1,4-dioxin-2-ones and 1,4-Dioxan-2-ones

3-Alkyl-6-methyl-2,3-dihydro-1,4-dioxin-2-ones reacted with acetyl chloride in the presence of zinc(II) chloride to give the corresponding 3-alkyl-5-acetyl-6-methyl-2,3-dihydro-1,4-dioxin-2-ones. Oxidation of the latter with hydrogen peroxide in formic acid, followed by treatment with magnesium bromide, afforded 3-alkyl-6-methyl-1,4-dioxane-2,5-diones. Successive chlorination and dechlorination of 6-hydroxymethyl-1,4-dioxan-2-ones yielded 6-methylene-1,4-dioxan-2-ones.     

Synthesis of New Substituted 2,3-Dihydro-1,4-dioxin-2-ones and 1,4-Dioxan-2-ones

3-Alkyl-6-methyl-2,3-dihydro-1,4-dioxin-2-ones reacted with acetyl chloride in the presence of zinc(II) chloride to give 5-acetyl-3-alkyl-6-methyl-2,3-dihydro-1,4-dioxin-2-ones. Oxidation of the latter with hydrogen peroxide in formic acid, followed by treatment with magnesium bromide, afforded 3-alkyl-6-methyl-1,4-dioxane-2,5-diones. Chlorination of 6-hydroxymethyl-1,4-dioxan-2-ones with thionyl chloride and subsequent dehydrochlorination led to formation of 6-methylene-1,4-dioxan-2-ones.     

1,4-Dihydro-1λ5,4λ5-[1,4]diphosphinine und ein 1,4-Dihydro-1λ3,4λ3-[1,4]diphosphinin

1,4-Dihydro-1λ⁵,4λ⁵-[1,4]diphosphinines and a 1,4-Dihydro-1λ³,4λ³-[1,4]diphosphinine Reaction of thio- or dithiocarbonic acids with ethinyl amino phosphanes leads to 1,4-dihydro-1λ⁵,4λ⁵-[1,4]diphosphinine-1,4-disulfides. By this route compounds 4, 7 , and 8 have been prepared. Desulfurization of 4 with tri-n-butylphosphane results in 1,2,4,5-tetraphenyl-1,4-dihydro-1λ³,4λ³-[1,4]-diphosphinine 5 , which can be oxidized with tert-butyl-peroxide to the corresponding dioxide, 6 . From the reaction mixture of phenyl-phenylethinyl diethylamino phosphane and thioacetamide compound 4 and the unsymmetrical 1,4-dihydro-1λ⁵,4λ⁵-[1,4]diphosphinine 9 were isolated. Properties, nmr, ir and mass spectra of all new products are reported. A mechanism for the formation of 9 is suggested. The results of the X-ray structure determination of 8 and 9 are described.