Synthesis of 3,3′‐Di(2‐Pyridyl)‐1,1′‐Bi‐2‐Naphthol Derivatives
摘要:
A new kind of (S)-3,3'-dipyridyl BINOLs (3a-d) with C-2-symmetry were synthesized in 79-84% yields by Suzuki coupling of the diboronic acid dipinacol ester (S)-1 containing a (S)-binaphthyl group with bromopyridine derivatives (2a-d) followed by hydrolysis.
制备了一系列吡啶-2-酚盐-6-(σ-芳基)[O CH 2 N,C] 4族双(苄基)预催化剂,具有柔性的O,N-给体螯合物,并通过多核NMR进行了表征光谱学。这些络合物采用C 1对称性,对二氟取代的σ-芳基Ti(IV)衍生物进行的可变温度1 H NMR实验表明,涉及七元螯合环倒置并伴随着苄基构象变化的流变过程( Δ ģ ‡ = 62.6千焦摩尔-1)。通过X射线晶体学研究确定的Zr(IV)亲戚的分子结构,发现[O CH]的“准子午线”配位严重扭曲2 N,C]配体和苄基部分的几乎垂直取向。已经与甲基铝氧烷(MAO)和硼酸三苯甲基酯一起进行了烯烃聚合研究。使用干燥的MAO(250当量)作为助催化剂和7 atm的乙烯压力,CF 3取代的Ti(IV)催化剂显示出良好的活性(在75°C时为680 g mmol –1 h –1; M w = 3.4×10 2 kg mol –1, M w / M n =
A new class of N-doped ionic PAHs<i>via</i>intramolecular [4+2]-cycloaddition between arylpyridines and alkynes
作者:Ravindra D. Mule、Aslam C. Shaikh、Amol B. Gade、Nitin T. Patil
DOI:10.1039/c8cc05743e
日期:——
Reported herein, for the first time, is a copper-promoted intramolecular [4+2]-cycloaddition cascade to access ionic N-doped polycyclic aromatic hydrocarbons (PAHs) with tunable emission wavelengths. It is shown that the reaction can be made catalytic with respect to Cu(OTf)2 when an external oxidant, Selectfluor, was used.
Magnetite@MCM‐41 nanoparticles as support material for Pd‐
<i>N</i>
‐heterocyclic carbene complex: A magnetically separable catalyst for Suzuki–Miyaura reaction
coupled plasma–optical emission spectroscopy (ICP‐OES) analysis. The catalytic activity of Magnetite@MCM‐41@NHC@Pd heterogeneous catalyst done on Suzuki–Miyaurareactions of aryl halides with different substituted arylboronic acid derivatives. All coupling reactions afforded excellent yields and up to 408404 Turnover Frequency (TOF) h−1 in the presence of 2 mg of Magnetite@MCM‐41@NHC@Pd catalyst (0.0564 mmol g−1
Selective palladium-catalysed arylation of 2,6-dibromopyridine using N-heterocyclic carbene ligands
作者:D. Prajapati、C. Schulzke、M. K. Kindermann、A. R. Kapdi
DOI:10.1039/c5ra10561g
日期:——
A selective palladium-catalysed arylation of 2,6-dibromopyridine has been developed by employing N-heterocyclic carbene ligands. Selective mono-arylation was performed in water/acetonitrile solvent system at ambient temperature with catalyst loading of 0.1 mol%. This reaction was also found to proceed smoothly in water although at a slightly elevated temperature of 80 °C. 2,6-Disubstituted and diversely
Fe3O4@SBA-15@NHC-Pd. The TEM images of the catalyst showed the existence of palladium nanoparticles immobilized in the catalyst's structure, while no reducing agent was used. The NHC moieties in the catalyst structure could be stabilize Pd(0) nanoparticles prevents agglomeration. The magnetic catalyst was effectively used in the Suzuki–Miyauracross-couplingreaction of substituted phenylboronic acid derivatives
合成了一种新型 Pd-NHC 功能化磁性 Fe 3 O 4 @SBA-15@NHC-Pd,并将其用作 Suzuki-Miyaura C-C 键形成反应中的高效非均相催化剂。Fe 3 O 4 @SBA-15@NHC-Pd 通过 X 射线衍射 (XRD)、X 射线光电子能谱 (XPS)、傅里叶变换红外 (FTIR) 光谱、扫描电子显微镜 (SEM)、透射电子显微镜进行表征(TEM)、能量色散 X 射线分析 (EDX)、热重分析 (TGA)、差热分析 (DTA)。电感耦合等离子体发射光谱 (ICP-OES) 分析用于确定 Fe 3 O 4中 Pd (0.33 wt%) 的准确量@SBA-15@NHC-PD。催化剂的 TEM 图像显示存在固定在催化剂结构中的钯纳米颗粒,而没有使用还原剂。催化剂结构中的 NHC 部分可以稳定 Pd(0) 纳米颗粒,防止聚集。磁性催化剂有效地用于取代苯基硼酸衍生物与(杂)芳基溴化物的
N-heterocyclic carbene Pd(II) complex supported on Fe3O4@SiO2: Highly active, reusable and magnetically separable catalyst for Suzuki-Miyaura cross-coupling reactions in aqueous media
presence of 2 mg of Fe3O4@SiO2@NHC@Pd-MNPs catalyst (0.0197 mmolg−1, 0.00394 mmol%Pd) at 80 °C in 2-propanol/H2O (1:2). In addition, the magnetic nano Fe3O4@SiO2@NHC@Pd-MNPs catalyst was easily recovered by using an external Nd-magnet and reused for the Suzukicross-couplingreactions. The catalyst showed strong structural and chemical stability and was reused six times without losing its catalytic activity