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本文研究了在双(新 基环戊二烯基)二氯钛催化下异丙基溴化镁与芳基酮或酯和α,β-不饱和酮或酯的反应, 发现还原反应中优势, (NMCp)2-TiCl2催化下格氏试剂对酯的还原, 其产物取决于催化剂的量, 同时, 还改进了双(新 基环戊二烯基)二氯钛的合成方法, 本文还提及了反应可能通过自由基历程。 相似文献
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本文报道在双环戊二烯基二氯化钛(Cp_2TiCl_2)催化下,Grignard试剂选择还原腈的反应。首次实现了用过渡金属络合物催化选择还原腈,是一种合成醛的新方法。最后还提出了可能的反应机理。 相似文献
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设计了一种由2,3-二氯-5,6-二氰基-1,4-苯醌(DDQ)和NaN02组成的复合催化剂,该催化剂在9,10-二氢葸氧化脱氢生成蒽的反应中表现出很高的催化活性和选择性.在120℃和1.3MPaO2下反应8h,9,10二氢蒽转化率达到99%以上,葸的选择性为99%.采用红外光谱和核磁共振方法对催化氧化脱氢的反应历程进行了研究.结果表明,9,10-二氢蒽氧气氧化脱氢生成蒽的反应是通过DDQ/DDQH2和NO2/NO两个氧化还原对的电子传递来推动的,以DDQ/NaNO2为催化剂可以有效催化9,10-二氢蒽氧化脱氢生成蒽. 相似文献
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设计了一种由 2,3-二氯-5,6-二氰基-1,4-苯醌(DDQ)和NaNO2组成的复合催化剂,该催化剂在9,10-二氢蒽氧化脱氢生成蒽的反应中表现出很高的催化活性和选择性. 在120 ℃和1.3 MPa O2下反应 8 h, 9,10-二氢蒽转化率达到99%以上,蒽的选择性为99%. 采用红外光谱和核磁共振方法对催化氧化脱氢的反应历程进行了研究. 结果表明, 9,10-二氢蒽氧气氧化脱氢生成蒽的反应是通过DDQ/DDQH2和NO2/NO两个氧化还原对的电子传递来推动的,以DDQ/NaNO2为催化剂可以有效催化9,10-二氢蒽氧化脱氢生成蒽. 相似文献
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很容易从醛和四溴化碳及三苯膦反应制备的1,1-二溴-1-烯烃在有机合成中是一个非常重要的原料.它广泛地应用于在钯催化下与有机硼酸、有机锡化合物、炔烃、有机锌试剂和Grignard试剂的交叉偶联反应[1-4].除此之外,1,1-二溴-1-烯烃与三丁基锡化氢的氢解反应,1,1-二溴-1-烯烃被氢负离子的还原,1,1-二溴-1-烯烃与金属钐和二碘化钐进行的还原脱溴反应,1,1-二溴-1-烯烃与胺的反应业已报道[5,6].Shen近来研究了钯催化下1,1-二溴-1-烯烃在不同膦配体的存在下于DMF溶液中的自身偶联反应和与末端炔烃的交叉偶联反应[7]. 相似文献
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自由基氟烷基化是向有机分子中引入氟烷基的一类非常重要的方法,也是目前有机化学研究的热点之一.近几年来,由于广泛的官能团兼容性和温和的反应条件等优点,可见光促进的氧化还原催化反应得到了长足的发展,已经成为化学键的构建和活化的有力工具.因此,光氧化还原催化的自由基氟烷基化反应,作为向有机化合物中引入氟烷基的有效途径,受到了广泛关注.本文报道了我们发展的氟烷基砜作为一类方便易得的新型氟烷基自由基前体,在可见光氧化还原催化下实现对烯烃的自由基氟烷基化反应.该反应可以高效地向芳基烯烃中引入三氟甲基、二氟甲基、1,1-二氟乙基、苯基二氟甲基等各种含氟烷基基团,并实现对芳基烯烃的双官能团化转化. 相似文献
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The structural stability of 2-phenyl- and 2-phenoxyethanols were investigated at the DFT-B3LYP/6-311G**, MP2 and MP4(SDQ) levels of theory. From the calculations at the three levels of theory 2-phenylethanol and 2-phenoxyethanol were predicted to exist predominantly in non-planar gauche conformations. For 2-phenylethanol the lowest energy Gg1 structure was predicted to be stabilized by an interaction between the hydroxyl H atom and the phenyl ring. For 2-phenoxyethanol the Ggg1 structure was predicted to be strongly stabilized by dipolar interactions between the hydroxyl H atom and the phenoxy O atom of the alcohol. For both alcohols the planar trans structure with minimum steric interactions between the CH2 groups was predicted to be significantly higher in energy than the ground state gauche structure of the alcohols. The dipolar interactions are reported to play more important role than steric ones in stabilizing the molecules. The vibrational frequencies of each of the two alcohols in its lowest energy gauche structure were computed at the B3LYP level and tentative vibrational assignments were made for their normal modes on the basis of the calculated and experimental data. 相似文献
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[reaction: see text] Fluoranthene 2 and heptacycle 3 are easily accessible from the reaction of diyne 1 and norbornadiene (NBD) in the presence of the rhodium catalyst. The unusual [(2+2)+(2+2)] adduct 3 was confirmed by the X-ray crystal structure analysis. 相似文献
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Hua Guo Yu Ting Hu Da Qiang Cang Yi Jin Li Xin Wang Xiang Li Cheng Hao Bai Yan Bing Zong 《中国化学快报》2010,21(2):229-233
<正>Two calculation models of mass action concentrations for CaO-MgO-SiO_2-Al_2O_3-Cr_2O_3 penta-slag was presented whether 3CaO·Cr_2O_3·3SiO_2 was existence or not.Equilibrium mass action concentration of each element structure was gained.And the models results were compared with experimental activity.The final results illustrated the model without 3CaO·Cr_2O_33SiO_2 was suit for reality.The model could response the element structure of slag as well. 相似文献
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Fuwa Y Endo T Wakeshima M Hinatsu Y Ohoyama K 《Journal of the American Chemical Society》2010,132(51):18020-18022
The crystal, electronic, and magnetic structures of the cobalt oxyselenide La(2)Co(2)O(3)Se(2) were investigated through powder neutron diffraction measurements and band structure calculations. This oxyselenide crystallizes in a tetragonal layered structure with space group I4/mmm. The Co ion is sixfold-coordinated by two oxide ions and four selenide ions, and the face-sharing CoO(2)Se(4) octahedra form Co(2)OSe(2) layers. The band structure calculations revealed that the Co ion is in the divalent high-spin state. Rietveld analysis of the neutron diffraction profiles below 200 K demonstrated that the Co moments have a noncollinear antiferromagnetic structure with the propagation vector k = (?, ?, 0). The ordered magnetic moment was determined to be 3.5 μ(B) at 10 K, and the directions of the nearest-neighbor Co moments are orthogonal each other in the c plane. 相似文献
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The molecular structure of 2-chloro-1,3-dithia-2-phospholane was determined using gas-phase electron diffraction and ab initio calculations. The heteroring in the molecule has an asymmetric structure like a symmetric P-envelope twisted about the C-C bond with an axial P-Cl bond. Geometric parameters of the molecule and mean vibration amplitudes were determined. The molecular structure of 2-chloro-1,3-oxathia-2-phospholane was predicted. The molecule in the gas phase has two conformers [twisted C(O)- and C(S)-envelope] with an axial P-Cl bond. 相似文献
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利用三苯基氯化锡和2,6-吡啶二甲酸在三乙胺存在下以1:1摩尔比反应,合成了离子型有机锡化合物{[Ph~2Sn]~2[2,6-Py(CO~2)]~3H~2O}^2^-[HNEt~3]^+~2。通过元素分析、红外光谱和核磁共振氢谱对其结构进行了表征。用X射线单晶衍射测定了该化合物的晶体结构。化合物为单斜晶系,空间群P2~1/n,a=1.7073(7)nm,b=1.7447(7)nm,c=2.5333(10)nm,β=109.694(7)°,Z=4,V=6.824(5)nm^3,D~c=1.282g/cm^3,μ=0.793mm^-^1,F(000)=2696,R~1=0.0563,WR~2=0.1539。化合物中两个锡原子呈七配位畸变五角双锥构型。生物活性测试结果表明,该化合物具有较强的体外抗肿瘤活性。 相似文献
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The title compound was prepared by annealing molybdenum powder with an excess of tin. Single-crystals were obtained by dissolving the tin-rich matrix in hydrochloric acid. They are Pauli paramagnetic. The crystal structure was determined from single-crystal X-ray diffractometer data: P6222, a = 548.8(1) pm, c = 1417.1(2) pm, Z = 6, R = 0.036 for 18 variable parameters and 389 structure factors. MoSn2 is only the second representative of the hexagonal Mg2Ni-type structure. The relation of the structure to the CuAl2-type is discussed. 相似文献