双活性中心催化剂的制备及催化合成炔丙基胺

Preparation of Propargylamines Catalyzed by Heterogeneous Catalysts with Double Catalytic Sites

以2,6-吡啶二甲酸和醋酸镍为原料,采用水热法合成了超分子配位聚合物Ni_2(2,6-NDC)2_(H_2O)_5·2H_2O(CP-Ni-NDC);然后分别以HAuCl_4和AgNO_3为前体,采用浸渍法制备了具有双活性中心的催化剂Au@CP-Ni-NDC和Ag@CP-Ni-NDC.采用X射线衍射、红外光谱、热重分析、透射电子显微镜、X射线光电子能谱、电感耦合等离子体原子发射光谱和NH_3程序升温脱附等方法对这2种催化剂进行表征,并考察了其在醛、炔和胺三组分偶联(A^3)反应合成炔丙基胺类化合物过程中的催化活性.实验结果表明,CP-Ni-NDC中的Ni与2,6-吡啶二甲酸络合形成了聚合物,层与层之间由氢键和π-π键作用形成三维超分子结构;催化剂4.49%Au@CP-Ni-NDC和3.43%Ag@CP-Ni-NDC存在路易斯酸-Au(或路易斯酸-Ag)双活性中心,有较高的催化合成炔丙基胺的活性,在120℃反应10 h,苯甲醛、苯乙炔和六氢吡啶发生A^3反应制备1-(1,3-二苯基-2-丙炔基)-哌啶的产率分别为63%和43%,转化数(Turnover number,TON)分别为9.9和4.8(基于总Au或总Ag含量).催化剂4.49%Au@CP-Ni-NDC和3.43%Ag@CP-Ni-NDC对于带有不同官能团的芳香醛和脂肪醛均具有较好的适应性,且可以重复使用4次.

The supramolecular coordination polymer Ni_2（2,6-NDC）2（H_2O）_5·2 H_2O（CP-Ni-NDC） was synthesized by hydrothermal method from 2,6-pyridinedicarboxylic acid and nickelous acetate.Then,Au@CP-Ni-NDC and Ag@CP-Ni-NDC catalysts with double catalytic sites were prepared with HAuCl_4 and AgNO_3 as precursors by impregnation method.The two catalysts were characterized by single crystal X-ray diffraction,powder X-ray diffraction（XRD）,infrared spectroscopy（IR）,thermogravimetric analysis（TG）,transmission electron microscopy（TEM）,X-ray photoelectron spectroscopy（XPS）,inductivity coupled plasma-atomic emiss ions spectrometry（ICP-AES） and temperature-programmed desorption（NH_3-TPD）.X-Ray crystallographic results reveal that CP-Ni-NDC is a one-dimensional chain,which further assembles into a three-dimensional supramolecular network via the π-π stacking interaction and hydrogen bonds.IR spectra,NH_3-TPD and XPS results indicated that 4.49% Au@CP-Ni-NDC and 3.43% Ag@CP-Ni-NDC contains Lewis acid-Au（Ag） double catalytic sites.The catalytic performance of the catalysts were examined in one-pot synthesis of structurally divergent propargylamines by three component coupling of aldehyde,alkyne and amine（A^3） in 1,4-dioxane.The substrate scope,catalyst reusability and possible mechanism were investigated.The results indicated that 4.49% Au@CP-Ni-NDC and 3.43% Ag@CP-Ni-NDC displyed good catalytic activity.The yields of propargylamines were 63% and 43% over 4.49% Au@CP-Ni-NDC and 3.43%Ag@CP-Ni-NDC at 120 ℃ within 10 h,respectively.Taking into account the total metal content of the catalyst,the TON numbers calculated were 9.9 and 4.8,respectively.4.49% Au@CP-Ni-NDC and 3.43%Ag@CP-Ni-NDC have good catalytic activities for aromatic aldehydes and aliphatic aldehydes.And the catalysts of 4.49%Au@CP-Ni-NDC and 3.43% Ag@CP-Ni-NDC could be recovered easily by centrifugation and reused four times.