MCM-41固载胺钯配合物的制备及对Heck反应催化性能的研究

以MCM-41分子筛作为固载材料, 经氨基功能化后与各种钯化合物形成一系列MCM-41载钯配合物, 采用XRD, XPS等技术对其结构及表面性能进行了表征, 研究了催化剂的制备条件等因素对催化Heck芳基化反应性能的影响; 以共轭烯烃和各种芳基碘的Heck芳基化反应考察了MCM～NH₂•Pd(0, II)配合物的催化性能. 结果表明, MCM-41的结构没有被破坏, MCM～NH₂载钯配合物具有较高的催化活性和立体选择性, 在较低的温度(70～90 ℃)下, 可高产率地生成一系列取代的反式产物.     

聚-ω-(甲硒基)十一烷基硅氧烷钯(0)配合物的合成与催化性能

ω-氯代十一烷基三乙氧基硅烷依次用气相法二氧化硅固载、与甲硒基钠和氯化钯作用, 再用水合肼还原, 合成了气相法二氧化硅负载的聚-ω-(甲硒基)十一烷基硅氧烷钯(0)配合物. 该钯(0)配合物对丙烯腈和丙烯酸与芳基碘的Heck芳基化反应具有很高的催化活性, 为各种肉桂腈和肉桂酸的立体选择合成提供了方便实用的新途径.     

配合物[Pd(phen)Cl2]与腺嘌呤的键合作用研究

合成并表征了固体三元配合物[Pd(phen)Cl₂] 1. 以1和DNA的组成小分子腺嘌呤(ade)反应, 获得双核配合物单晶[Pd₂(phen)₂(ade)₂]Cl₂•4.5H₂O (2). 配合物2为正交晶系, 空间群为Pnma, 晶胞参数a＝2.1709(9) nm, b＝1.4378(6) nm, c＝1.2274(5) nm, α＝β＝γ＝90°, V＝3.8311(3) nm³, D_c＝1.729 g/cm³, Z＝4, F(000)＝2004, R₁＝0.0766, wR₂＝0.1526. phen配体以两个氮原子与钯(II)离子配位, 按生物学原子规范标号, ade以N(3), N(9)原子与钯(II)离子桥联配位, 形成双核混配型配合物.     

溶剂对钯催化的叔丁基乙炔低聚反应化学选择性的调控作用

报道了溶剂对钯催化的叔丁基乙炔低聚反应化学选择性的调控作用. 反应可在苯-正丁醇双组分溶剂体系中顺利进行, 当双组分溶剂体系中苯占优势比例时, 反应发生递次的三分子炔烃顺式插入, 经由顺式s-烯钯中间体生成环三聚产物1,3,5-三叔丁基苯; 而当双组分溶剂中正丁醇组分上升至一定比例, 反应选择性生成(3Z,5Z)-2,2,7,7-四甲基- 3,6-二氯-3,5-辛二烯或(3Z,5Z)-2,2,7,7-四甲基-3,6-二溴-3,5-辛二烯, 这是由于正丁醇可显著加快C—Pd σ键的断裂, 并与叔丁基乙炔、σ-烯钯中间体形成弱氢键作用力, 同时也与Pd(II)和Cu(II)等离子存在配位效应. 在强极性质子溶剂H₂O中, 反应生成偶联双炔: 2,2,7,7-四甲基-3,5-辛二炔. 文中就反应溶剂体系、钯铜催化剂及反应可能机理等分别进行了探讨.     

N-皮考林酰肼及其双核钯配合物的晶体结构和荧光性质

合成了配体N-皮考林酰肼(简写为Hphz)及其双核钯配合物[Pd₂(phz)₂Cl₂]. X射线衍射实验结果表明, 配体和配合物晶体均属于单斜晶系, 空间群分别为C 2/c和P 2₁/c, 分子式分别为C₆H₇N₃O和C₁₂H₁₂Cl₂N₆O₂Pd₂. 晶体学参数, Hphz, a＝1.9245(2) nm, b＝0.38927(2) nm, c＝1.8073(2) nm, b＝107.255(2)°, V＝1.2931(2) nm³, Z＝8, D_c＝1.409 Mg/m³, F(000)＝576, μ(Mo Kα)＝0.102 mm^－1, R＝0.0541, wR＝0.1762; [Pd₂(phz)₂Cl₂], a＝1.48274(9) nm, b＝1.44797(9) nm, c＝0.73951(5) nm, b＝92.719(3)°, V＝1.5860(2) nm³, Z＝4, D_c＝2.329 Mg/m³, F(000)＝1072, μ(Mo Kα)＝2.62 mm^－1, R＝0.0262, wR＝0.0555. 在配合物[Pd₂(phz)₂Cl₂]分子内, 两个钯(II)原子, 均呈畸变的N₃Cl平面正方形配位构型, 晶体内通过分子间氢键N—H…Cl 作用形成一维链状结构, 分子间吡啶环存在相互作用. 量子化学从头算方法计算结果表明, 分子内及分子间的金属钯之间也存在相互作用. 红外光谱表明, 配体在形成配合物后, ν(C＝O)和ν(C＝N)红移, ν(C—N)蓝移, 荧光光谱表明, 配合物金属对配体n-π*激发(310 nm)引起的发射峰有较大的影响.     

一种经MCM-41负载双齿膦钯(0)配合物催化的羰基化Suzuki偶联合成二芳酮的新途径

在催化量的MCM-41负载双齿膦钯(0)配合物存在下,芳基碘化物和芳基硼酸、一氧化碳在常压下能顺利进行羰基化Suzuki偶联反应,高产率地生成了各种二芳酮化合物。MCM-41负载双齿膦钯(0)配合物具有比PdCl2(PPh3)2 更高的活性和选择性,且可回收再用10次其活性基本不变,为各种功能化二芳酮的合成提供了方便实用的新途径。     

芳基与烷基亚砜钯(II)配合物π反馈效应的DFT研究

应用DFT方法对二苯基亚砜(DPSO)和二己基亚砜(DHSO)的钯(II)配合物进行了理论计算。结果表明中心金属钯与亚砜之间存在d-π^*反馈键，而且二苯基亚砜钯(II)配合物中的π反馈键比二己基亚砜钯(II)配合物强，即亚砜的取代基对其钯(II)配合物的π反馈键有显著的影响。以BHandH/6-31+G^**(Pd，3-21G^*)//BHandH/6-31G^*(Pd，3-21G^*)方法对相应的亚砜钯(II)配合物进行单点计算时，配合物trans-PdCl₂(DPSO)₂ 的π反馈键轨道能为-10.695 eV，而trans-PdCl₂(DHSO)₂的π反馈键轨道能量为-10.320 eV。利用电子给体NH₃或电子受体CO配位体置换亚砜钯(II)配合物里的一个亚砜配体后，Pd(II)-DHSO配合物的Pd-S配位键长的变化明显小于Pd(II)-DPSO配合物的Pd-S配位键长变化值，进一步说明在Pd-DPSO配合物中的π反馈效应强于相应的Pd-DHSO配合物。     

功能化MCM-41负载双齿氮钯催化剂的制备及其在Suzuki偶联中的应用

首先胺功能化修饰介孔材料MCM-41,再与二-(吡啶-2-基-)甲酮缩合成席夫碱,最后通过Pd(OAc)2配位制备了MCM-41负载双齿氮钯配合物,采用X射线衍射(XRD)以及X射线光电子能谱(XPS)对其结构表征.该负载催化剂在以二甲苯为溶剂,K2CO3为碱以及n-Bu4NF用作添加剂的Suzuki偶联中表现出优越的催化性能.     

通过接枝苄基磺酸在MCM-41上固载手性Mn(salen)配合物

首先通过两步后合成处理,在MCM-41上接枝苄基磺酸;然后,以苄基磺酸为过渡产物,用手性Mn(salen)配合物修饰处理,得到了苄基磺酸轴向负载手性Mn(salen)配合物的MCM-41;实现了在廉价且温和条件下均相手性Mn(salen)催化剂的非均相化。采用X射线衍射(XRD)、低温N₂吸附-脱附、红外光谱、热重-差示扫描量热(TG-DSC)分析、电感耦合等离子体发射光谱(ICP)和酸度滴定等对样品进行了表征。结果表明,手性Mn(salen)配合物成功固载在MCM-41上,且MCM-41的介孔结构和Mn(salen)配合物的手性特征仍然保留。以间氯过氧苯甲酸为氧化剂,考察了所得固载型催化剂对α-甲基苯乙烯的不对称环氧化催化性能,结果表明在0 ℃反应2 h,催化剂用量为0.02 mmol,无需加入轴向配体N-甲基吗啉氮氧化物(NMO)的条件下对映体过量(enantiomeric excess,e.e.)值可达99%以上,转化率为77%。归因于苄基磺酸基起到了很好的轴向配体作用。经适当处理,固载型催化剂在循环使用5次后e.e.值依然有71%,表现出较好的活性和重复使用性能。     

锌(Ⅱ)配合物Zn(2-PMBBA)2(Phen)的合成、电化学、磁性及荧光性能研究

以2-(对甲基苯甲酰基)苯甲酸(2-PMBBA)和1,10-邻菲啰啉(Phen)为配体合成了一个新的锌(Ⅱ)配合物Zn(2-PMBBA)₂(Phen)。该配合物晶体属正交晶系,空间群Pccn,晶胞参数:a=1.3716(4)nm,b=1.3368(4)nm,c=1.9287(5)nm,V=3.5364(17)nm³,D_c=1.360g·cm^-3,Z=4,μ(MoKα)=0.746mm^-1,F(000)=1496,最终偏离因子R₁=0.0358,wR₂=0.0861。在标题配合物中,中心锌(Ⅱ)离子的配位数是4,处于变形的四面体配位环境中,这是不多见的。本工作还测定了标题配合物的电化学、磁性及荧光性能。结果表明:循环伏安过程中,配合物的电子转移是不可逆的,对应的电极反应是Zn(Ⅱ)/Zn(0);在300~7K,配合物有抗磁性;当激发波长为224nm时,配合物在450和472nm处有强的荧光发射峰。     

Dicyano-Functionalized MCM-41-Supported Palladium Complex as An Efficient Catalyst for Allylation of Aldehydes and Ketones

Dicyano-functionalized MCM-41-supported palladium complex was prepared from dicyano-functionalized MCM-41 and palladium chloride. This complex exhibited high catalytic activity in the allylation of aldehydes and ketones with allylic chlorides in the presence of SnCl2. This polymeric palladium complex can be recovered and reused without noticeable loss of activity.     

A novel MCM-41-supported sulfur palladium(0) complex catalyst for Sonogashira coupling reaction

A novel MCM-41-supported sulfur palladium(0) complex was conveniently prepared from commercially available and cheap γ-mercaptopropyltriethoxysilane via immobilization on MCM-41, followed by reacting with palladium chloride and then the reduction with hydrazine hydrate. This complex exhibited excellent performance in Sonogashira coupling reaction.     

Vinylation of aryl iodides catalyzed byMCM-41supported poly-g-mercaptopropylsiloxanePd(0,II)complexes

Summary MCM-41-supported poly-γ-mercaptopropylsiloxane palladium (0,II) complexes were easily prepared from poly-γ-mercaptopropylsiloxane and MCM-41 in chloroform, followed by coordination to palladium chloride in ethane at room temperature. These catalysts are highly active and stereoselective for vinylation of aryl iodides with olefins, and give a variety of trans substituted products in high yields at 70^oC, and can be reused without loss in activity.</o:p>     

Effect of auxiliary chemicals on preparation of silica MCM-41

Silica MCM-41 materials were prepared hydrothermally by using 1,3,5-trimethylbenzene (MS) or 1,3,5-triisopropylbenzene (TI) as an auxiliary chemical. The BJH poressize of MCM-41 increased up to 12 nm with increasing amounts of MS. However, MCM-41 materials prepared with MS displayed irregular pore arrangements and a half of these materials exhibited low thermal and hydrothermal stabilities. On the other hand, MCM-41 materials prepared with TI as an auxiliary chemical displayed regular pore arrangements and high thermal and hydrothermal stabilities, but their BJH pore sizes did not go over 4.0 nm (intrinsic value; ca. 5 nm). MCM-41 prepared with TI together with a small amount of MS (TI/MS/SiO₂=1.5/0.5/1) displayed regular pore arrangements and high thermal and hydrothermal stabilities. Its BJH pore size was 4.7 nm (intrinsic value; ca. 6 nm).     

An imidazolium ionic liquid having covalently attached an oxime carbapalladacycle complex as ionophilic heterogeneous catalysts for the Heck and Suzuki-Miyaura cross-coupling

An oxime carbapalladacycle, analogous to that used as catalyst in homogeneous phase, has been derivatized to increase its ionophilicity by introducing an imidazolium group covalently attached through a chain at the complex. The resulting complex is soluble in 1-butyl-3-methylimidazolium ionic liquid (bmimPF₆) and not extractable by ether. The catalytic activity of this palladium complex in bmimPF₆ is, however, unsatisfactory and only increases marginally in bmimPF₆/supercritical CO₂. This limitation has been overcome by supporting this imidazolium palladium complex on high surface area Al/MCM-41 aluminosilicate, whereby a solid active catalyst for the Suzuki cross-coupling has been obtained. Reusability and stability over reuse for this Al/MCM-41-supported catalyst have been studied.     

Carbonyl allylation of aldehydes and ketones with allylic chlorides catalyzed by immobilization of palladium in MCM-41

The heterogeneous carbonyl allylation of aldehydes and ketones with allylic chlorides was achieved in DMF using SnCl₂ as reducing agent at 25-40 °C in the presence of a 3-(2-aminoethylamino)propyl-functionalized MCM-41-immobilized palladium(II) complex [MCM-41-2N-Pd(II)], yielding a variety of homoallylic alcohols in good to high yields. This heterogeneous palladium catalyst exhibited higher activity than (N-propylethylenediamine)PdCl₂ and can be recovered and recycled by a simple filtration of the reaction solution and used for at least 5 consecutive trials without any decreases in activity.     

水热法合成MCM-41分子筛时添加辅助烃的影响

０前言中孔ＭＣＭ－４１分子筛是Ｍｏｂｉｌ公司１９９２年开发的一种具有２－１０ｎｍ孔径的新型分子筛材料。由于其独特的孔径范围和表面特性,相关研究已经成为国际分子筛研究领域的热点课题,对它的合成、表征和催化作用已进行了许多研究［１～７］。Ｍｏｂｉｌ公司的...     

MCM-41-supported bidentate phosphine palladium(0) complex: a highly active and recyclable catalyst for the Sonogashira reaction of aryl iodides

The first MCM-41-supported bidentate phosphine palladium(0) complex has been prepared. This complex is a highly efficient catalyst for Sonogashira reaction and can be reused at least 10 times without any decrease in activity.     

Selective Oxidation of Cyclic Hydrocarbons with H2O2 over Ti- and V-Containing Zeolites and Mesoporous Catalysts

Ti- and V-containing MFI, MEL and MCM-41 catalysts were studied in the oxidation of cyclohexane, cyclohexene, naphthalene, tetralin, decalin and phenol with H₂O₂. Although TS-1 and TS-2 exhibited the highest activity and selectivity in the oxidation of _n -hexane and 1-hexene, cyclohexene could only be oxidized effectively on the MCM-41 silicates. Since the oxidation of condensed aromatic systems over Ti- and V-containing MFI and MEL zeolites runs to difficulties, MCM-41 type catalysts may be offered for these reactions.