Functional Group Interconversion: Decarbonylative Borylation of Esters for the Synthesis of Organoboronates

A new and efficient nickel‐catalyzed decarbonylative borylation reaction of carboxylic acid esters with bis(pinacolato)‐diboron has been developed. This transformation allows access to structurally diverse aryl as well as alkenyl and alkyl boronate esters with high reactivity, broad substrate scope, and excellent functional‐group tolerance. Further experiments show that this protocol can be carried out on a gram scale and applied to orthogonal synthetic strategies.     

Hydride Transfer Enables the Nickel-Catalyzed ipso-Borylation and Silylation of Aldehydes

Nickel-catalyzed ipso-borylations and silylations of aldehydes are described for the first time. The new functional-group interconversion protocol is characterized by its scalability, functional-group tolerance and wide substrate scope, including examples of late-stage functionalization of complex molecules. The key for the successful reaction outcome is the use of a ketone as a hydride acceptor that intercepts the nickel hydride to undergo a reductive pathway, thus allowing formation of the desired C−B and C−Si bonds.     

双二茂铁甲氨基醇的合成及其硅烷基化

;双二茂铁甲醇;硅基化;双二茂铁甲氨基醇的合成及其硅烷基化     

Decarbonylative CC Bond‐Forming Reactions of Saccharins by Nickel Catalysis: Homocoupling and Cycloaddition

Decarbonylation of saccharins by nickel catalysis enables two kinds of C?C bond‐forming reactions; homocoupling of saccharins to form biaryls and cycloaddition with alkynes to form benzosultams. The former represents the first reported nickel‐catalyzed decarbonylative C?C homocoupling reaction, whereas the latter constitutes a powerful method to pharmaceutically relevant benzosultams. The reactions proceed with good functional‐group tolerance and excellent regioselectivity.     

Na2EDTA返滴定法测定铜镍合金中的镍含量

采用Na₂EDTA返滴定法测定铜镍合金中的镍含量,用柠檬酸钠、硫代硫酸钠和酒石酸作掩蔽剂,丁二酮肟沉淀分离,以二甲酚橙为指示剂,加入过量的Na2EDTA,用氯化锌标准溶液返滴定,能很好地分离铜及其他杂质的干扰。方法用于测定铜镍合金中的镍含量,测定结果的相对标准偏差(RSD,n=9)为0.046%~0.24%,加标回收率为99.3%~101%。能够满足日常样品的检测要求。     

Novel Approaches to Metallization of Cellulose by Reduction of Cellulose-Incorporated Copper and Nickel Ions

Summary: Copper and nickel nanoparticles were synthesized in the insoluble microcrystalline cellulose support by reduction of metal ions with several reducers in various media resulting in cellulose-metal nanocomposites. Wide-angle X-ray scattering results showed that supramolecular structure of cellulose did not change. Crystalline Cu₂O and Cu⁰ nanoparticles were prepared with reducers NaBH₄ and N₂H₄ · H₂SO₄, CuO nanoparticles – with cellulose itself as a reducer. Crystalline Ni⁰ nanoparticles were synthesized with N₂H₄ · 2HCl and NaBH₄; Ni⁰ nanoparticles in amorphous form were prepared with KH₂PO₂ · H₂O. SEM revealed large agglomerates of metal particles on the fibre surface. ASAXS and TEM have shown the nanoparticles to be in the range 5–55 nm.     

波长色散X射线荧光光谱法快速测定纺织面料中的铬、镍、铜

建立波长色散X射线荧光光谱快速检测纺织面料中铬、镍、铜的方法。利用树脂将标准贴衬织物复合到玻璃熔片上,在制备好的织物样片上滴加铬、镍、铜标准溶液,采用波长色散X射线荧光光谱仪检测。根据元素滴加量的变化建立校准曲线,铬、镍、铜3种元素的含量分别在0~853,0~853,0~1 706μg/g范围内与荧光强度呈良好的线性关系,相关系数r2大于0.99。方法回收率为95.0%~98.8%,测定结果的相对标准偏差为3.2%~4.8%(n=6)。利用该方法检测纺织面料中重金属元素含量,方法简便,结果准确,检测成本低。     

手性铜催化剂的制备及在环丙烷羧酯酯不对称合成中的应用

３类手性配体ｄ－１０－樟脑磺酸及其衍生物，α－（－）－羟蒎酮及其衍生物，又恶唑啉６衍生物分别与铜（Ⅱ）形成手性铜配合物，催化重氮乙酸酯与１，１－二苯乙烯或异丁烯的环丙烷化加成反应，得到光学活性环丙羧酸酯，不对称诱导最高可达９５％ｅ．ｅ．。     

Nickel and Copper Catalyzed ipso-Phosphonodifluoromethylation of Arylboronic Acids with BrCF2P(O)(OEt)2 for the Synthesis of Phosphonodifluoromethylarenes

A convenient method for the direct ipso-phosphonodifluoromethylation of arylboronic acids via nickel-copper co-catalysis is disclosed. This work, which utilizes inexpensive first row transition metals, represents a facile alternative to the traditional palladium catalyzed approach. The method utilizes inexpensive commodity chemicals and substrates while tolerating a variety of biologically relevant functional groups. Structurally diverse phosphonodifluoromethylarenes are furnished in good yields under short reaction times. Control experiments to probe possible reaction pathways are also included.     

Competitive Sorption of Copper and Nickel Ions from Aqueous Solution Using Peat

Bicomponent aqueous solutions of copper and nickel ions have been used to investigate the sorption of metal ions onto peat. Peat, a low cost sorbent, has shown a high capacity for the sorption of single component metal ions attributed to extensive carboxylic acids within its structure. Copper and nickel ions were selected as typical metals in the effluents of electroplating industries. The effects of competitive sorption in batch systems were studied at various metal ion concentrations. In this study the Butler and Ockrent model was modified using a coefficient, . Two models were developed based on the interaction coefficient . The first model incorporates a constant fixed factor for each metal ion into the Butler-Ockrent equation. The second model incorporates a variable factor into the Butler-Ockrent equation; this interaction factor varies as a function of sorbent surface coverage. Predicted equilibrium data are found to be in excellent agreement with experimental values using both modified models for various mole ratios of copper and nickel ions in competitive sorption.     

ICP-AES法测定镍铜合金中的Fe,Mn,Cr,Nb

建立了ICP–AES法测定镍铜合金中Fe,Mn,Cr,Nb元素的分析方法。进行了基体元素Ni,Cu及共存元素对分析元素的光谱干扰研究,分别选择259.940,257.610,283.563,316.340 nm作为分析谱线,确定内标用量为2.00 mL。测定结果的相对标准偏差为0.48%～4.71%(n=8),加标回收率为95.0%～103.4%。该法满足分析要求。     

Thermogravimetric Evidence of Nickel or Copper Isomorphously Substituted into a Zeolite

The synthesis of pure silica ZSM-5 has been modified to produce highly crystalline material in the protonated form, necessary for catalytic activity, directly from a low water fluoride gel. Tetrahedrally co-ordinated divalent species of nickel and copper have been synthesised as salts of large organic cations and increasing mole fractions incorporated into the zeolite gels. The products have been analysed and characterised using simultaneous thermogravimetric and derivative thermogravimetric analysis (TG-DTG). The thermal decomposition under nitrogen of the metal associated cations, tetraethylammonium (TEA⁺), occluded within the zeolite channels is indicative and characteristic of the incorporation of heteroatoms into the zeolite framework. Anomalous losses in the systems can be explained by Jahn–Teller distortions. The mass losses increased with increased metal loading and were consistent with those reported in full water system, analysis also confirmed that the material was hydrophobic and thermally stable. Analysis by X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray fluorescence (XRF), Fourier transform infrared spectroscopy (FTIR) and Atomic Absorption Spectroscopy (AAS) has confirmed the reliability of TG-DTG as a diagnostic tool. The maximum levels of substitution achieved were (mass%) Ni 3.93 and Cu 4.38. This revised version was published online in August 2006 with corrections to the Cover Date.     

trans-Selective Aryldifluoroalkylation of Endocyclic Enecarbamates and Enamides by Nickel Catalysis

Efficient methods for the dicarbofuntionalization of the cyclic alkenes 2-pyrroline and 2-azetine are limited. Particularly, the dicarbofunctionalization of endocyclic enecarbamates to achieve fluorinated compounds remains an unsolved issue. Reported here is a nickel-catalyzed trans-selective dicarbofunctionalization of N-Boc-2-pyrroline and N-Boc-2-azetine, a class of endocyclic enecarbamates previously unexplored for transition metal catalyzed dicarbofunctionalization. The reaction can be extended to six- and seven-membered endocyclic enamides. A variety of arylzinc reagents and bromodifluoroacetate, and its derivatives, undergo the reaction, providing straightforward and efficient access to an array of pyrrolidine- and azetidine-containing fluorinated amino acids and oligopeptides, which may have applications in the life sciences.     

担载铜镍催化剂氢溢流现象的TPR研究

本文采用TPR(Temperature Programmed Reduction)作为主要表征手段,对担载铜、镍催化剂循环还原-氧化(RedoX过程)处理前后的样品进行了表征.其次也进行了TPR测试后所得金属铜(镍)催化剂催化还原其前体氧化物(auto-catalysed reduction)的研究.发现这两种研究方式所得种种有趣结果都可归属于氢溢流现象.RedoX处理后,其TPR谱上金属氧化物的还原峰向低温区位移,并伴有总耗氢量的增加.其中峰位移可归属于Redox过程未被氧化完全的还原态金属(特别是铜)离解氢分子,形成的氢原子溢向邻近的金属氧化物(如CuO),使其在较低温度下还原;而耗氢量的增加则可归属氢原子向载体(SiO_2或Al_2O_3)的溢流,载体被活化使总耗氢量增加.上述现象可认为是同一颗粒间的氢溢流.在自催化还原过程中出现的氢溢流现象(低温区出现新还原峰和总耗氢量增加)可认为是催化剂不同颗粒间的氢溢流.总之TPR可以作为研究同一颗粒和不同颗粒间发生氢溢流行之有效的方法.     

相转移催化合成酯基取代酞菁铜及其光导性能

酞菁配合物的大π键共轭体系使其具有独特的物理化学性能．但酞菁的难溶性,限制了其进一步的研究和应用．Baker等首次制备了可溶性酞菁单分子膜,并将其应用到光电池中;随后,已有大量的相关研究报道．作为常见的可溶性酞菁衍生物,酯基取代酞菁由于含酯基的前体物质高温分解而不能采用直接缩合的方法,     

镍配合物[N,N]NiBr2的合成及其催化乙烯齐聚研究

 吡啶甲醛类化合物与苯胺类化合物缩合形成有机配体［N，N］，\r\n它与金属镍的卤化物NiBr2作用可形成稳定的配合物［N，N］NiBr2．这\r\n种配合物在含铝助催化剂存在下显示出较高的催化乙烯齐聚的活性，所\r\n得乙烯齐聚物具有较高的支化度和较低的α－烯烃含量．实验结果表明\r\n，吡啶环与苯环上的取代基对催化反应的活性具有不同的影响，助催化\r\n剂的种类及用量、反应溶剂和乙烯压力等对该体系的催化反应活性及产\r\n物结构具有直接影响．研究结果表明，通过调节催化聚合反应的工艺条\r\n件，有可能实现控制聚合产物的分子量和分子量分布，以及提高产物中\r\nα－烯烃的含量等．     

氯化镍催化的醚的酰化开裂反应

在某些金属盐存在下,醚可与酰氯反应生成酯,早期文献中对于此类反应曾有过报道,其中所用的金属盐有三氯化铁或氯化锌,其相对用量较大,酯的得率较差。其后,Alper等提出用第五族金属羰基化合物和酰氯,如Mo(CO)_4-RCOCl为试剂,进行醚的开裂;近期则有Pri-Bar等用Pd(Ⅱ)-R_3SnX-