Metal Triflate-Catalyzed Cationic Benzylation and Allylation of 1,3-Dicarbonyl Compounds
作者:Masahiro Noji、Yosuke Konno、Keitaro Ishii
DOI:10.1021/jo0705216
日期:2007.7.1
The rare earth metal and hafnium triflate-catalyzed secondary benzylation and allylation of 1,3-diketones, ketoesters, and ketoamides are described. The procedure was carried out under non-anhydrous conditions. Various 1-phenylethyl cations were generated from substituted 1-phenylethanols using 0.5 mol % of the metal triflates in CH3NO2. The cations reacted with 1,3-diketones and ketoesters to give
描述了稀土金属和三氟甲磺酸ha催化的1,3-二酮,酮酸酯和酮酰胺的二次苄基化和烯丙基化。该程序在无水条件下进行。在CH 3 NO 2中使用0.5摩尔%的金属三氟甲磺酸酯,由取代的1-苯基乙醇生成各种1-苯基乙基阳离子。。阳离子与1,3-二酮和酮酸酯反应生成苄基化产物,收率很高。根据GC分析,可根据三氟甲磺酸的路易斯酸度和反应温度通过选择催化剂轻松优化反应条件。叔烷基化的二酮和相应的酮酸酯也被苄基化,以57-84%的收率得到具有季碳原子的产物。与二酮和酮酯反应中使用的那些相比,酮酰胺反应需要更强的路易斯酸。在Hf(OTf)4的存在下,研究了在芳环上具有各种取代基的苄醇与作为二酮的二苯甲酰甲烷(2b)的反应。富电子苄醇与2b反应以86-96%的产率收率,缺电子醇则以79-65%的收率得到所需的产物。尽管具有强的吸电子基团,但是1-(4-硝基苯基)乙醇的反应以61%的收率得到了相应的产物。也可以
The heterobimetallic catalyst [Pd(COD)Cl-SnCl3] efficiently promotes the intermolecular hydroarylation of alpha-methyl substituted arenes (otherwise known to be dimerized/polymerized in presence of Lewis Acids) with indoles and other O-, S-heteroarenes leading to Markovnikov adducts. The reaction takes place under air and moisture insensitive condition. (C) 2012 Elsevier Ltd. All rights reserved.
Organocatalyzed Friedel–Crafts arylation of benzylic alcohols
作者:J. Adam McCubbin、Oleg V. Krokhin
DOI:10.1016/j.tetlet.2010.02.151
日期:2010.5
Electron-rich aromatic and heteroaromatic rings are functionalized directly with a variety of benzylic alcohols under mild conditions. The reaction is catalyzed by commercially available pentafluorophenylboronic acid, which is stable under ambient conditions and recoverable. The reaction itself is highly atom economical and produces water as the only byproduct. A Friedel-Crafts mechanism is proposed. (C) 2010 Elsevier Ltd. All rights reserved.
Calcium-Catalyzed Hydroarylation of Alkenes at Room Temperature
作者:Meike Niggemann、Nicola Bisek
DOI:10.1002/chem.201001375
日期:——
trisubstituted styrene derivatives were reacted to give the desired diarylalkanes within less than an hour at roomtemperature in the presence of 2.5 mol % of Ca(NTf2)2/Bu4NPF6 (see scheme). Additionally, the highly reactive calcium catalyst was successfully applied for the hydroarylation of dienes and even trisubstituted olefins.
钙催化剂的发展:在室温下,在2.5 mol%Ca(NTf 2)2存在下,在不到一小时的时间内,使各种贫电子,富电子和三取代的苯乙烯衍生物反应生成所需的二芳基烷烃/ Bu 4 NPF 6(请参阅方案)。另外,高反应性钙催化剂已成功地用于二烯甚至三取代烯烃的加氢芳基化反应。
A Novel Synthetic Route to 2-Arylalkanoic Acids by a Ruthenium-Catalyzed Chemoselective Oxidation of Furan Rings
Friedel-Crafts alkylation of 2-methylfuran with 1-arylalkanols without employing anhydrous conditions. The chemoselective oxidation of the furanring in 1-arylalkylfurans to carboxylic acid was then investigated. In a solvent system of hexane-EtOAc/H 2 O (1:3:4), the furanring was selectively oxidized with 7 equivalents of NaIO 4 by using 0.5 mol% RuCl 3 as catalyst to give 2-arylalkanoic acids in good yields