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在路易斯酸催化下,碳硼烷分别与对氰基溴化苄、三苯基膦在甲苯溶液里回流,前者反应中,制备得碳硼烷的硼端与对氰基苄基中的亚甲基直接偶联的产物1,通过调整催化剂的含量,可以显著地提高含B-Cl键的产物2的产率;与三苯基膦的反应中,碳硼烷失去一个硼顶,并与三苯基膦中的P原子直接偶联,生成含B-P键的巢式碳硼烷衍生物3。对此两类化合物进行了核磁、质谱、红外及单晶衍射等表征。化合物1和2中均发现碳硼烷的CH与N形成CH…N氢键和CH…π的弱作用,其中化合物2中,还存在CH…Cl。在巢式化合物3中,发现碳硼烷的CH参与了罕见的CH…HC相互作用。这类反应成功合成了含有B-C、B-Cl、B-P键的碳硼烷衍生物。 相似文献
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《无机化学学报》2014,(10)
在路易斯酸催化下,碳硼烷分别与对氰基溴化苄、三苯基膦在甲苯溶液里回流,前者反应中,制备得碳硼烷的硼端与对氰基苄基中的亚甲基直接偶联的产物1,通过调整催化剂的含量,可以显著地提高含B-Cl键的产物2的产率;与三苯基膦的反应中,碳硼烷失去一个硼顶,并与三苯基膦中的P原子直接偶联,生成含B-P键的巢式碳硼烷衍生物3。对此两类化合物进行了核磁、质谱、红外及单晶衍射等表征。化合物1和2中均发现碳硼烷的CH与N形成CH…N氢键和CH…π的弱作用,其中化合物2中,还存在CH…Cl。在巢式化合物3中,发现碳硼烷的CH参与了罕见的CH…HC相互作用。这类反应成功合成了含有B-C、B-Cl、B-P键的碳硼烷衍生物。 相似文献
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含碳硼烷膦氧配体镍、铱化合物的合成与表征 总被引:1,自引:1,他引:0
碳硼烷双膦配体L1分别与三苯基膦氯化镍(NiCl2(PPh3)2)和1,5-环辛二烯氯化铱(IrCl(COD))在空气中反应生成含巢式碳硼烷膦氧配体的镍、铱化合物1和2。本文对此两个化合物进行了核磁、质谱、红外及单晶衍射等表征。化合物1中溶剂分子氯仿与主体结构存在着常见的Cl…H氢键作用和较少见的CH…π作用,化合物2是首例以膦氧配体形成的Ir(Ⅰ)配合物,同时由于金属的差别导致了碳硼烷双膦配体被氧化程度的不同形成了新颖的碳硼烷[P,O]和[O,O]配体。 相似文献
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碳硼烷和碳硼炔金属配合物中的金属-碳键具有不同于经典金属-碳键的化学性质.一方面,二十面体碳硼烷独特的电子和空间效应使得碳硼烷金属配合物中的金属-碳键不参与和不饱和分子的反应 另一方面,在一定条件下具有大空间位阻的碳硼笼可以诱导某些碳-碳偶联反应.然而,碳硼炔金属配合物中的金属-碳键能与多种不饱和分子发生反应,其反应模式取决于中心金属离子的电子构型.本文简要总结了我们近期在这方面的研究进展. 相似文献
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该文运用高分辨质谱技术对实时直接分析(Direct analysis in real time,DART)离子化条件下碳硼烷化合物的质谱行为进行了研究,对碳硼烷化合物DART高分辨质谱中所得到的同位素峰簇进行了表征与归属。研究结果表明,选取的碳硼烷化合物在DART负离子条件下均能得到较好的质谱信号,这可能与硼笼结构的“缺电性”有关。含10个B原子的碳硼烷化合物形成的离子同位素峰簇信号中,通常情况下相对丰度最高的同位素峰中含2个10B以及8个11B。将碳硼烷化合物高分辨质谱分析的精确m/z数据信息与图谱中同位素峰轮廓分析相结合,是碳硼烷化合物有效的质谱定性分析与表征策略。 相似文献
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碳十硼烷及其衍生物的反应性及应用 总被引:1,自引:0,他引:1
碳十硼烷(C2B10H12)是由2个C原子和10个B原子组成的二十面体笼状结构大分子,有邻位、间位和对位三种异构体。碳十硼烷庞大的体积以及类芳香族三维刚性结构使它具有优异的高温稳定性和化学稳定性,良好的溶解性使其具有广泛而灵活的应用。本文总结了近年来碳十硼烷和碳十硼烷衍生物在C原子、B原子上的化学反应性以及在环加成和金属络合方面的研究。另外,由于碳十硼烷衍生物特殊的立体结构,优异的耐高温性、热氧化性及高硼含量,本文综述了碳十硼烷衍生物近年来在功能材料、催化剂及生物医药等多个领域的应用进展。 相似文献
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Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction
Laurent Gavara Thomas Boisse Jean-Pierre Hénichart Adam Daïch Philippe Gautret 《Tetrahedron》2010,66(38):7544-5571
In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments. 相似文献
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KMnO4-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields. 相似文献
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N. A. Nedolya 《Chemistry of Heterocyclic Compounds》2008,44(10):1165-1219
The review contains a concise historical account and information on the most significant researches undertaken by the staff
at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry
of Heterocyclic Compounds.
Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee.
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008. 相似文献
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Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields. 相似文献
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An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions. 相似文献
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Uroš Grošelj Mojca Žorž Amalija Golobič Branko Stanovnik Jurij Svete 《Tetrahedron》2013,69(52):11092-11108
A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives. 相似文献
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The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp3)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp2)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp2)?H and aliphatic 1,5- and 1,6-C(sp3)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp3)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp2)?H insertion. 相似文献
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Rebecca J. Burton Mandy L. CrowtherNeal J. Fazakerley Shaun M. FilleryBarry M. Hayter Jason G. KettleCaroline A. McMillan Paula PerkinsPeter Robins Peter M. SmithEmma J. Williams Gail L. Wrigley 《Tetrahedron letters》2013
The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines. 相似文献
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N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%). 相似文献