十二烷基硫酸根复合物的制备及电子转移催化剂应用

制备了三种聚烷基紫精-十二烷基硫酸根复合物(PRV-LS),用紫外光谱、顺磁共振波谱研究了复合物的氧化、还原行为,将复合物用作电子转移催化剂于异相体系(CH_2Cl_2-H_2O;1:1,20mL)考察了其诱导的偶氮苯还原。结果表明:复合物在异相条件被还原时,聚烷基紫精自由基(PRV~ ·)在LS成份的作用下发生相转移,复合物具有良好的诱导偶氮苯还原的能力。     

十二烷基硫酸根复合物的制备及电子转移催化剂应用

制备了三种聚烷基紫精-十二烷基硫酸根复合物(PRV-LS), 用紫外光谱、顺磁共振波谱研究了复合物的氧化、还原行为, 将复合物用作电子转移催化剂于异相体系(CH2Cl2-H2O; 1:1, 20mL)考察了其透导的偶氮苯还原。结果表明: 复合物在异相条件被还原时, 聚烷基紫精自由基(PRV^+)在LS成份的作用下发生相转移, 复合物具有良好的诱导偶氮苯还原的能力。     

新型5-溴嘧啶衍生物的选择性合成

对甲苯磺酰氯与三甘醇单甲酯完成酯化反应,再与对溴苯酚缩合制得对溴苯基三甘醇单甲醚(3);3与硼酸甲酯完成取代反应、酸解后在Pd(PPh3)4催化下与5-溴-2-碘嘧啶(5)在甲苯中通过Suzuki偶联反应选择性地合成了5-溴-2-对(甲基三甘醇基)苯基嘧啶(1a),收率73%。以1-十二烯和5为主要原料,通过Suzuki偶联反应,一锅法选择性地合成了5-溴-2-十二烷基嘧啶(1b),收率82%。1a和1b未见文献报道,其结构经1HNMR,13C NMR和MS表征。     

新试剂1-(2-羟基-3,5-二硝基苯基)-3-[4-(苯基偶氮)苯基]-三氮烯的合成及与季铵盐型阳离子表面活性剂的显色反应

合成了新试剂1-(2-羟基-3,5-二硝基苯基)-3-[4(苯基偶氮)苯基]-三氮烯(HDNPAPT),研究了该试剂在NaOH介质中与阳离子表面活性剂漠化十六烷基三甲铵(CTMAB)、溴化十六烷基吡啶(CPB)、溴化十二烷基二苄铰(DDMBAB)形成1:3的紫红色离子缔合物显色体系.测定了显色体系表面活性剂的临界胶束浓度、表观摩尔吸光系数ε_(max)、符合比尔定律的范围.探讨了微量阳离子表面活性剂CMTAB、CPB和DDMBAB的测定方法,结果满意.     

3-溴咔唑的绿色合成新工艺研究

以咔唑为原料,通过N-乙酰基保护、溴化、脱乙酰基制备出高纯3-溴咔唑。溴化体系采用溴化钠饱和溶液―浓硫酸―双氧水,考察了反应温度、双氧水用量、溴化钠用量及反应时间等因素对反应的影响。结果表明,溴化较佳工艺为N-乙酰基咔唑、溴化钠、硫酸和双氧水的物质的量比为1.0∶1.1∶0.6∶1.2,20℃反应5 h,收率90%,纯度98%。脱酰保护较佳条件为N-乙酰基-3-溴咔唑与盐酸的物质的量比为1∶10,回流反应2 h,收率97%,产品纯度为99.5%。总收率为83.8%。利用熔点和1H-NMR对各步产物进行表征。     

黄酮类化合物研究(ⅩⅣ)——溴代异黄酮合成中的脱溴反应

我们曾报道2-溴间苯二酚在BF_3催化下酰化时的脱溴现象。本文在以下述反应制备6-溴代异黄酮时发现4-溴间苯二酚脱溴现象更为显著。     

5-溴-6-甲氧基-2-丙酰基萘的钯催化氢化脱溴

溴甲氧基丙酰基萘;5-溴-6-甲氧基-2-丙酰基萘的钯催化氢化脱溴     

气相色谱-串联质谱法测定2-氰基溴苄中3-氰基溴苄和4-氰基溴苄的含量

建立了气相色谱-串联质谱法测定苯甲酸阿格列汀关键起始物料2-氰基溴苄中基因毒性杂质3-氰基溴苄和4-氰基溴苄含量的分析方法。采用50%苯基-50%二甲基聚硅氧烷为固定液的VF-17MS毛细管柱(30m×0.25mm,0.25μm)进行程序升温;进样口温度260℃;以多反应监测(MRM)模式检测。2种待测物均具有较好的线性关系,相关系数均大于0.998 0;检出限(3S/N)均为2.0μg·L^-1;3-氰基溴苄的回收率为92.1%~97.0%;4-氰基溴苄的回收率为102%~109%;供试品溶液、杂质对照品溶液和系统适用性溶液在室温(25℃)下放置18h内稳定。三批生产规模样品中均未检出3-氰基溴苄和4-氰基溴苄。建立的分析方法灵敏度高、分离度好、结果准确,可有效分离并测定2-氰基溴苄中的3-氰基溴苄和4-氰基溴苄含量,为苯甲酸阿格列汀的安全性提供了保障。     

4-溴吲哚-3-甲醛的合成

以2-甲基-3-硝基苯胺为原料,经重氮化反应先合成2-溴-6-硝基甲苯(1),1与N,N-二甲基甲酰胺二甲基缩醛经L-B吲哚合成法制得4-溴吲哚(3),3与N,N-二甲基甲酰胺和三氯氧磷起Vilsmeier-Hacck反应得4-溴吲哚-3-甲醛,总收率62．0％。其结构经^1H NMR和IR确证。     

1-溴-3-甲苯氧基-2-丙醇的Jones试剂氧化反应

本文采用易得的1-溴-3-甲苯氧基-2-丙醇(1a,1b和1c)经Jones试剂氧化反应,合成了1-溴-3-(4-甲基苯氧基)-2-丙酮(2a)、1-溴-3-(3-甲基苯氧基)-2-丙酮(2b)、1-溴-3-(2-甲基苯氧基)-2-丙酮(2c)化合物,并研究了这类反应的副产物。反应中,产物均经硅胶柱分离得到,IR,^1HNMR,MS确定其结构。产物酮(2a)、(2b)、(2c)非常不稳定,影响了元素分析的准确测定。     

Preparation, crystal structure, and thermal stability of the cadmium sulfide nanoclusters Cd6S44+ and Cd2Na2S4+in the sodalite cavities of zeolite A (LTA)

The crystal structure and thermal stability of two cadmium sulfide nanoclusters prepared in zeolite A (LTA) have been studied by XPS, TGA, and single-crystal and powder XRD. The crystal structures of Cd2.4Na3.2(Cd6S4)0.4(Cd2Na2S)0.6(H2O)> or =5.8[Si12Al12O48]-LTA (a = 12.2919(7) A, crystal 1 (hydrated)) and /Cd4Na2(Cd2O)(Na2O)/[Si12Al12O48]-LTA (a = 12.2617(4) A, crystal 2 (dehydrated)) were determined by single-crystal methods in the cubic space group Pm3m at 294(1) K. Crystal 1 was prepared by ion exchange of Na12-LTA in an aqueous stream 0.05 M in Cd2+, followed by washing in a stream of water, followed by reaction in an aqueous stream 0.05 M in Na2S. Crystal 2 was made by dehydrating crystal 1 at 623 K and 1 x 10(-6) Torr for 3 days. In crystal 1, Cd6S4(4+) nanoclusters were found in and extending out of about 40% of the sodalite cavities. Central to each Cd6S4(4+) cluster is a Cd4S4 unit (interpenetrating Cd2+ and S2- tetrahedra with near Td symmetry, Cd-S = 2.997(24) A, Cd-S-Cd = 113.8(12) degrees, and S-Cd-S = 58.1(24) degrees). Each of the two remaining Cd2+ ions bonds radially through a 6-ring of the zeolite framework to a sulfide ion of this Cd4S4 unit (Cd-S = 2.90(8) A). In each of the remaining 60% of the sodalite cavities of crystal 1, a planar Cd2Na2S4+ cluster was found (Cd-S/Na-S = 2.35(5)/2.56(14) A and Cd-S-Cd/Na-S-Na = 122(5)/92(7) degrees). Cd6S4(4+) and Cd2Na2S4+ are stable within the zeolite up to about 700 K in air. Upon vacuum dehydration at 623 K, all sulfur was lost (crystal 2). Instead as anions, only two oxide ions remain per sodalite unit. One bridges between two Cd2+ ions (Cd2O2+, Cd-O = 2.28(3) A) and the other between two Na+ ions (Na2O, Na-O = 2.21(10) A).     

Preparation of polyalkylviologen–polyanion complexes and their applications to the debromination of diphenyl bromomethane under heterophase condition

Several polyelectrolyte complexes were prepared by the reaction of polyalkylviologens [polyethylviologen (PEV²⁺), polypropylviologen (PPrV²⁺), and polybutylviologen (PBV²⁺)] with polyanions [sodium alginic (ALG), sodium polyacrylate (PAA), or sodium polystyrenesulfonate (PSS)]. These complexes were used as electron-transfer catalysts (ETC) on the debromination of diphenyl bromomethane (Ph₂CHBr) under heterophase condition [reductant: Na₂S₂O₄, in H₂O (liquid)-polyelectrolyte complex(S)—Ph₂CHBr in CH₂Cl₂]. The work showed that these complexes could induce the debromination of Ph₂CHBr to afford tetraphenyl ethane, and different polyanions in the complexes also affected the mediating abilities. © 1994 John Wiley & Sons, Inc.     

Generation of the CF3 radical from trifluoromethylsulfonium triflate and its trifluoromethylation of styrenes

The CF(3) radical was generated from the reaction of S-(trifluoromethyl)diphenylsulfonium triflate with Na(2)S(2)O(4) or HOCH(2)SO(2)Na under suitable conditions without further reduction. Based on this, a method for the synthesis of α-trifluoromethylated ketones has been successfully developed.     

Na5(In4S)(InS4)3.6H2O, a zeolite-like structure with unusual SIn4 tetrahedra

A hydrated sodium indium sulfide, Na5(In4S)(InS4)3.6H2O, has been prepared by hydrothermal synthesis. This material contains a tetrahedral sulfur site coordinated to four trivalent indium ions, an unusual bonding pattern not previously observed in open framework chalcogenides. The structure is related to the perovskite (CaTiO3) type with simultaneous substitutions of Ti by SIn4, O by InS4, and Ca2+ by [Na5(H2O)6]5+. It is a wide-gap semiconductor and shows photocatalytic activity under UV light for hydrogen generation from aqueous solution without use of any cocatalyst.     

1-butyl-3-methylimidazolium cobalt tetracarbonyl [bmim][Co(CO)4]: a catalytically active organometallic ionic liquid

An ambient temperature liquid transition metal carbonyl anion has been prepared in a metathesis reaction between [bmim]Cl ([bmim]+ = 1-butyl-3-methylimidazolium cation) and Na[Co(CO)4]; the ionic liquid catalyses the debromination of 2-bromoketones.     

Unprecedented stabilization of cobalt(II) in a tetrahedral S2O2 environment: the use of a redox-noninnocent ligand

The reaction of Zn(II) and Co(II) with thiosalicylic acid, o-HSC6H4COOH, and its methyl ester has led to the following complexes: [Zn(SC6H4COO)] (1), (NEt4)Na[Zn(SC6H4COO)2].H2O (2), (NEt4)2Na[Co(SC6H4COO)3].2H2O (3), (NEt4)3Na3[(Co(SC6H4COO)3)2].6MeOH (4), [Zn(SC6H4COOMe)2] (5), and [Co(SC6H4COOMe)n], n = 2 (6), 3 (7). These ligands have not allowed stabilization of Co(II) in a sulfur-oxygen coordination environment. The structures of complexes 2-4 and 7 have been determined crystallographically. Those of 2-4 show significant similarities such as the behavior of the -SC6H4COO- anion as chelating ligand and the involvement of sodium ions as a structural element. Thus, the structure of the [Na(Zn(SC6H4COO)2)(H2O)]- anion in complex 2 can be described as infinite chains of consecutive [Zn(SC6H4COO)2]2- metalloligands linked by [Na(H2O)]+ centers, that of the [Na(Co(SC6H4COO)3(H2O)2)]2(4-) anion in 3 as a centrosymmetric tetranuclear Co2Na2 dimer with a (CoIII(S[symbol: see text]O)3)Na(mu-H2O)2Na(CoIII(S[symbol: see text]O)3) core, and that of the pentanuclear [Na3(Co(SC6H4COO)3)2(MeOH)6]3- anion in 4 as two dinuclear [(CoIII(S[symbol: see text]O)3)Na(MeOH)3] fragments linked to a central sodium ion, which appears to be the first structurally characterized example of a NaS6 site. The use of the o-HSC6H4COOMe ligand allowed the synthesis of [Co(SC6H4COOMe)2] (6) but not its full structural characterization. Instead, [Co(SC6H4COOMe)3] (7) was obtained and structurally characterized. It consists of mononuclear molecules containing an octahedral CoIIIS3O3 core. The selection of 2,2-diphenyl-2-mercaptoacetic acid as ligand with reductive properties has afforded the first mononuclear complex containing a CoIIS2O2 core and thus an unprecedented model for Co(II)-substituted metalloproteins containing tetrahedral MS2O2 active sites. The synthesis and full structural characterization of the isostructural complexes (NEt4)2[Zn(Ph2C(S)COO)2] (8) and (NEt4)2[Co(Ph2C(S)COO)2] (9) show that they consist of discrete [M(Ph2C(S)COO)2]2- anions, with a distorted tetrahedral coordination about the metal. In addition, the stability conferred by the ligand on the CoIIS2O2 core has allowed its characterization in solution by paramagnetic 1D and 2D 1H NMR studies. The longitudinal relaxation times of the hyperfine-shifted resonances and NOESY spectra have led to the assignment of all resonances of the cobalt complex and confirmed that it maintains its tetrahedral geometry in solution. Magnetic measurements (2-300 K) for complex 9 and 9.2H2O are in good agreement with distorted tetrahedral and octahedral environments, respectively.     

Selective oxidative debenzylation of mono- and oligosaccharides in the presence of azides

When using benzyl ethers as permanent protecting groups in oligosaccharide synthesis selective oxidative debenzylation with NaBrO(3) + Na(2)S(2)O(4) under biphasic conditions is efficient and compatible with anomeric azides and many other functions.     

Syntheses and chemistry of hypervalent cyclo-R4Sb4, cyclo-(RSbE)n[R = 2-(Me2NCH2)C6H4, E = O, S] and precursors

The cyclostibane R(4)Sb(4)(1)(R = 2-(Me(2)NCH(2))C(6)H(4)) was synthesized by reduction of RSbCl(2) with Mg in THF or with Na in liquid NH(3). The reaction of 1 with [W(CO)(5)(THF)] gives the stibinidene complex RSb[W(CO)(5)](2)(2). RSbCl(2) and (RSbCl)(2)E [E = O (6), E = S (8)] react with KOH or Na(2)S in toluene/water to give the heterocycles (RSbE)(n)[E = O, n= 3 (3); E = S, n= 2 (4)]. The chalcogeno-bridged compounds of the type (RSbCl)(2)E [E = O (6), E = S (8)] were synthesized by reaction of RSbCl(2) with KOH or Na(2)S in toluene/water, but also by reaction of RSbCl(2) with the heterocycles (RSbE)(n). The compounds (RSbI)(2)O (7) and (RSbBr)(2)S (9) were prepared via halogen-exchange reactions between (RSbCl)(2)E and NaI (E = O) or KBr (E = S) or by reactions between RSbI(2) and KOH or RSbBr(2) and Na(2)S. The reaction of cyclo-(RSbS)(2) with W(CO)(5)(THF) in THF results in trapping of the cis isomer in cyclo-(RSbS)(2)[W(CO)(5)](5). The solution behaviour of the compounds was investigated by (1)H and (13)C NMR spectroscopy. The molecular structures of compounds 1-7 and 9 were determined by single-crystal X-ray diffraction.