Gold-Catalysed Oxyarylation of Styrenes and Mono- and<i>gem</i>-Disubstituted Olefins Facilitated by an Iodine(III) Oxidant
作者:Liam T. Ball、Guy C. Lloyd-Jones、Christopher A. Russell
DOI:10.1002/chem.201103061
日期:2012.3.5
1‐Hydroxy‐1,2‐benziodoxol‐3(1H)‐one (IBA) is an efficient terminal oxidant for gold‐catalysed, three‐component oxyarylation reactions. The use of this iodine(III) reagent expands the scope of oxyarylation to include styrenes and gem‐disubstituted olefins, substrates that are incompatible with the previously reported Selectfluor‐based methodology. Diverse arylsilane coupling partners can be employed
Rhodium and Iridium Nanoparticles Entrapped in Aluminum Oxyhydroxide Nanofibers: Catalysts for Hydrogenations of Arenes and Ketones at Room Temperature with Hydrogen Balloon
作者:In Soo Park、Min Serk Kwon、Kyung Yeon Kang、Jae Sung Lee、Jaiwook Park
DOI:10.1002/adsc.200600651
日期:2007.8.6
showed high activities in the hydrogenation of various arenes and ketones under mild conditions. Selective hydrogenation was possible for bicyclic and tricyclic arenes in high yields. The catalysts were active at room temperature even with a hydrogenballoon. Also, the catalysts showed high turnover frequency (TOF) values under solventless conditions at 75 °C under 4 atm hydrogen pressure: ca. 1700 h−1 in
可循环利用的金属纳米颗粒催化剂,氢氧化铝中的铑[Rh / AlO(OH)]和氢氧化铝中的铱[Ir / AlO(OH)],是从容易获得的试剂中简单制备的。在温和的条件下,该催化剂在各种芳烃和酮的氢化中显示出高活性。双环和三环芳烃的选择性加氢可能以高收率进行。该催化剂即使在具有氢气球的情况下在室温下也具有活性。此外,催化剂显示无溶剂的条件下高转化频率(TOF)值在75℃下4个大气压的氢气压力:约 1700小时-1在苯的氢化中。此外,Rh / AlO(OH)可以重复使用至少10次而不会失去活性。通过透射电子显微镜(TEM),粉末X射线衍射(XRD),电感耦合等离子体(ICP),能量色散X射线分析(EDX),X射线光电子能谱(XPS),氮吸附来表征催化剂和氢化学吸附实验。铑和铱粒子的大小分别估计为3–4 nm和2–3 nm。这些催化剂的氢氧化铝氧化铝纤维的表面积为500–600 m 2 g -1。
Gold-Catalyzed Oxidative Coupling Reactions with Aryltrimethylsilanes
作者:William E. Brenzovich、Jean-François Brazeau、F. Dean Toste
DOI:10.1021/ol102194c
日期:2010.11.5
During continuing studies with a novel oxidative gold oxyarylation reaction, arylsilanes were found to be competent coupling partners, providing further evidence for an intramolecular electrophilic aromatic substitution mechanism. While providing yields complementary to those of the previously described boronic acid methods, the use of trimethylsilanes reduces the observation of homocoupling byproducts
Tuning Reactivity and Site Selectivity of Simple Arenes in C–H Activation: Ortho-Arylation of Anisoles via Arene–Metal π-Complexation
作者:Paolo Ricci、Katrina Krämer、Igor Larrosa
DOI:10.1021/ja510260j
日期:2014.12.31
Current approaches to achieve siteselectivity in the C–H activation of arenes involve the use of directing groups or highly electron-poor arenes. In contrast, simple arenes, such as anisole, are characterized by poor reactivity and selectivity. We report that π-complexation to a Cr(CO)3 unit enhances the reactivity of anisoles providing an unprecedented ortho-selective arylation. This mild methodology
for hydrogenation of polycyclicaromatichydrocarbons (PAHs) containing 2–4 rings undermild reaction conditions. These compounds were partially hydrogenated with good to excellent selectivities just by optimizing the reaction conditions. The influence of the nature of substituents present in different positions of naphthalene on the selectivity of hydrogenation was also studied. Hydrogenation of products