多壁碳纳米管负载钯(II)催化剂催化Suzuki-Miyaura反应的研究

多壁碳纳米管(MWNTs)负载钯(II)催化剂以乙醇/水(V/V=1∶1)混合溶液为溶剂,室温条件下,高效催化卤代芳烃与苯硼酸的Suzuki-Miyaura偶联反应。该催化剂绿色环保,能够在循环使用5次后仍有较好的稳定性。     

1,2-二苯基乙烯基膦钯(Ⅱ)催化的 Sonograshira交叉偶联反应

合成了含有大位阻和富电子膦配体的1,2-二苯基乙烯基膦配体, 并研究了以1,2-二苯基乙烯基膦配体和二氯化二苯腈合钯(Ⅱ)为催化剂催化的Sonograshira交叉偶联反应.     

新型联苯类双膦配体的合成及钯催化Suzuki-Miyaura反应

以易得3-溴苯甲醚为原料经四步反应合成了新联苯双膦配体6,6'-二甲氧基-2,2'-二(二-2-吡啶基膦)-1,1'-联苯(DPP),且经氢谱、磷谱、碳谱和高分辨质谱表征.此配体的钯配合物对多种芳基溴和苯硼酸的Suzuki-Miyaura偶联反应表现出很高的催化性能,即使芳基溴有较大的空间位阻或者带有官能团取代基也能获得很好的结果.     

氯化四硫脲合钯配合物Pd[(NH2)2CS]4Cl2的晶体结构

The title compound， Pd[(NH₂)₂CS]₄Cl₂， has been synthesized and structurally characterized. It crystallizes in orthorhombic， Pna2(1) space group ， with M_r=481.79(C₄H₁₆Cl₂N₈PdS₄)， a=12.943(3)， b=8.283(2)， c=15.148(3)?， V=1623.9(6)?³， Z=4. The Pd(Ⅱ) ion has an square-planar geometry， and is coordinated by four S atom donors from four thiourea molecules. The two Cl^- anions found in the apical position balance the charge. In the solid state， the title compound forms three dimensional network structures through hydrogen bonds. The inter-molecular hydrogen bonds connect the {Pd[(NH₂)₂CS]₄}²⁺ and chloride ion to contribute to the stability of the structure. CCDC： 193379.     

氯化钯催化的交叉偶联反应

钯催化的交叉偶联反应已经成为有机合成化学中构建C-C键最重要的方法之一.其中,氯化钯及其配合物所组成的催化体系具有高效、高选择性、稳定以及价廉等优点,因而在交叉偶联反应中得到较为广泛的应用.综述了氯化钯及其配合物催化的交叉偶联反应,其中包括Suzuki反应、Stille反应、Hiyama反应和Kumada反应等.     

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.     

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.     

手性膦过渡金属配合物催化不对称交叉偶联反应的研究

自1973年Consiglio和Botteghi首次报道用(一)-DIOP的NiCl_2配合物催化芳基或乙烯基卤代物与仲烷基卤化镁交叉偶联生成光学活性的偶联产物以来,化学家们对不对称交叉偶联反应进行了深入研究。Hayashi等用手性二茂铁膦和手性β-氨基烷基膦的NiCl_2和PdCl_2配合物催化1-苯基乙基氯化     

金属配合物[MBr{(Ph2PCH2CH2)2C6H3}],[M=Pd(Ⅱ)、Pt(Ⅱ)]的合成及晶体结构

合成了一个新的双膦配位体2,6-双(二苯基膦乙基)溴苯,通过Pd     

双锌配合物Zn2(DTPB)Cl4水解DNA

本工作用光谱表征、电泳分离及高效液相色谱(HPLC)等方法考察了双锌配合物Zn₂(DTPB)Cl₄(DTPB=1,1,4,7,7-五(2′-苯并咪唑-2-基甲基)三氮杂庚烷)与DNA的结合及其导致的DNA水解断裂作用。结果表明Zn₂(DTPB)Cl₄是DNA水解的有效促进剂,以超螺旋DNA作为水解底物,其消失的反应符合准一级速率定律,初步估算其速率常数为2.4×10^-5s^-1     

In situ generation of palladium nanoparticles: ligand-free palladium catalyzed ultrafast Suzuki-Miyaura cross-coupling reaction in aqueous phase at room temperature

An ultrafast and highly efficient ligand-free Suzuki-Miyaura cross-coupling reaction between aryl bromides/iodides and arylboronic acids using palladium chloride as catalyst in PEG400/H₂O in air at room temperature has been developed. TEM showed that palladium nanoparticles were generated in situ from PdCl₂/PEG400/H₂O without use of other reductants. The catalyst system can be recycled to reuse three times with good yields.     

Pd(OAc)2/DABCO-catalyzed Suzuki-Miyaura cross-coupling reaction in DMF

The scope and limitations of the Pd(OAc)₂/DABCO (1,4-diaza-bicyclo[2.2.2]octane)-catalyzed Suzuki-Miyaura cross-coupling reactions have been demonstrated. The results showed that the effect of solvent had a fundamental influence on the reaction. In the presence of Pd(OAc)₂ and DABCO, both aryl bromides and aryl chlorides all worked well with arylboronic acids to form biaryls, heteroaryl-aryls, and biheteroaryls in moderate to excellent yields using DMF as the solvent. Additionally, the reactions of aryl bromides were conducted under relatively mild conditions.     

The highly efficient Suzuki-Miyaura cross-coupling reaction using cyclopalladated N-alkylferrocenylimine as a catalyst in aqueous medium at room temperature under ambient atmosphere

A series of N-alkyl-substituted cyclopalladated ferrocenylimines were used in palladium-catalyzed Suzuki-Miyaura cross-coupling reactions of aryl halides in room temperature and CH₃OH/H₂O media under aerobic conditions. As for the catalysts, the length of N-alkyl chains has no significant effect on the catalytic activity. Using 0.01 mol% of dimer 3a in the presence of K₂CO₃ as base offered excellent yields in the reaction of activated and non-activated aryl bromides with phenylboronic acid.     

Convenient synthesis of photochromic symmetrical or unsymmetrical bis(heteroaryl)maleimides via the Suzuki-Miyaura cross-coupling reaction

A general method for the synthesis of symmetrical or unsymmetrical bis(heteroaryl)maleimides by a one-pot procedure involving Suzuki-Miyaura cross-coupling sequence was developed on the basis of the reaction of 3,4-diiodo-1-benzyl-1H-pyrrole-2,5-dione with cyclic boronate esters using PdCl₂(dppf) as the catalyst. Photochromic properties of the products were examined.     

An inexpensive and highly stable ligand 1,4-bis(2-hydroxy-3,5-di-tert-butylbenzyl)piperazine for Mizoroki-Heck and room temperature Suzuki-Miyaura cross-coupling reactions

A bulky, inexpensive and simple bidentate ligand 1,4-bis(2-hydroxy-3,5-di-tert-butylbenzyl)piperazine (1) has been synthesized and characterized. The palladium catalyst was formed by combination of 1 with [Cl₂Pd(COD)] in a ratio of 1:1, tested in the Suzuki-Miyaura and Mizoroki-Heck cross-coupling reactions. Coupling of a variety of aryl bromides with phenylboronic acid using methanol as solvent at room temperature, or at 60 °C, gave generally high yields of coupled products. Coupling of aryl chlorides with organoboron reagent at 110 °C in DMF afforded good yields of biaryls under aerobic conditions. This non-phosphorus, air and moisture stable catalyst also displays good activity for Mizoroki-Heck coupling reaction in methanol at 60 °C with various aryl chlorides and bromides.     

Suzuki-Miyaura cross-coupling reaction of aryl bromides and chlorides with phenylboronic acid under aerobic conditions catalyzed by palladium complexes with thiosemicarbazone ligands

For the first time, palladium complexes with salicylaldehyde thiosemicarbazones were applied as catalyst precursors to the Suzuki-Miyaura reaction. These air and moisture stable phosphine-free systems efficiently catalyze the cross-coupling of aryl bromides and chlorides (from electron rich to electron poor) with phenylboronic acid in DMF/H₂O at 100 °C for 24 h, using Na₂CO₃ as base, without addition of free ligand or any promoting additive, and under aerobic conditions no significant homocoupling of phenylboronic acid to unsubstituted biphenyl was observed.     

Palladium(II)-N-heterocyclic carbene complex derived from proline towards Suzuki-Miyaura coupling reaction in water at room temperature

Palladium(II)-N-heterocyclic carbene complex 1 derived from proline has been proved to be a highly effective catalyst in the Suzuki-Miyaura coupling reaction of aryl iodides and bromides with arylboronic acids in water at room temperature. The reactions are tolerant towards various functional groups in the substrates. Moreover, the complex 1-catalyzed medium-scale (10.0 mmol) Suzuki-Miyaura reactions were also carried out and it was found that the complex was also effective enough in these cases.     

A polymer-supported salen-type palladium complex as a catalyst for the Suzuki-Miyaura cross-coupling reaction

A salen-type palladium(II) complex was readily immobilised onto a Merrifield resin. The supported complex is an effective recyclable heterogeneous catalyst for the Suzuki cross-coupling reaction without the use of phosphine ligands. Leaching of the metal into solution from the supported catalyst proved negligible.     

Triphenylphosphine chalcogenides as efficient ligands for room temperature palladium(II)-catalyzed Suzuki-Miyaura reaction

A simple catalytic system based on PdCl₂ and triphenylphosphine chalcogenides (PPh₃X; X = O, S, Se) is found to be highly effective (up to 97% isolated yield) in the room temperature Suzuki-Miyaura reactions. Under the same experimental conditions, triphenylphosphine chalcogenides as ligands show superior activities compared to free triphenylphosphine.     

[PdCl2{8-(di-tert-butylphosphinooxy)quinoline)}]: a highly efficient catalyst for Suzuki-Miyaura reaction

The complex [PdCl₂(P-N)] containing the basic and sterically demanding 8-(di-tert-butylphosphinooxy)quinoline ligand (P-N) is a highly efficient catalyst for the coupling of phenylboronic acid with aryl bromides or aryl chlorides. The influence of solvent and base has been investigated, the highest rates being observed at 110 °C in toluene with K₂CO₃ as the base. With aryl bromides the reaction rates are almost independent on the electronic properties of the para aryl substituents, on the contrary, reduced reaction rates are observed when bulky substituents are present on the substrate. Nevertheless the coupling of 2-bromo-1,3,5-trimethylbenzene with phenylboronic acid can be carried out to completion in 2 h using a catalyst loading of 0.02 mol %. Under optimized reaction conditions, turnover frequencies as high as 1900 h⁻¹ can be obtained in the coupling of 4-chloroacetophenone with phenylboronic acid; lower reaction rates are obtained with substrates bearing EDG substituents on the aryl group.