Rhodium-Catalyzed Borylation of Aryl 2-Pyridyl Ethers through Cleavage of the Carbon–Oxygen Bond: Borylative Removal of the Directing Group
作者:Hirotaka Kinuta、Mamoru Tobisu、Naoto Chatani
DOI:10.1021/ja511622e
日期:2015.2.4
diboron reagent results in the formation of arylboronic acid derivatives via activation of the C(aryl)-O bonds. The straightforward synthesis of 1,2-disubstituted arenes was enabled through catalytic ortho C-H bond functionalization directed by the 2-pyridyloxy group followed by substitution of this group with a boryl group. Several control experiments revealed that the presence of a sp(2) nitrogen
The nickel‐catalyzed borylation of aryl2‐pyridyl ethers via the loss of a 2‐pyridyloxy group is described. This method allows a 2‐pyridyloxy group to be used as a convertible directing group in C−H bond functionalization reactions. The nickel catalyst can also borylate arylmethyl 2‐pyridyl ethers, in which the stereochemistry at the benzylic position is retained in the case of chiral secondary benzylic
intermediacy of an Ir-boryl complex where the substrate C–Hactivation is the turnover determining step, intriguingly without any appreciable primary KIE. The method displays a broad range of substrate scope and functional group tolerance. Numerous late-stage borylation of various important molecules and drugs were achieved using this developed strategy. The borylated compounds were further converted into
一种 Ir 催化的芳烃(例如 2-苯氧基吡啶、2-苯胺基吡啶、苄胺、苄基哌嗪、苄基吗啉、苄基吡咯烷、苄基哌啶、苄基氮杂环己烷、α-氨基酸衍生物、氨基苯基乙烷衍生物和其他重要支架)的无配体邻位硼化的有效方法) 并开发了药物。正如通过使用动力学同位素研究和 DFT 计算进行的详细机理研究所揭示的那样,该反应通过一个有趣的机理途径进行。发现催化循环涉及 Ir-硼基络合物的中间体,其中底物 C-H 活化是转换决定步骤,有趣的是没有任何明显的初级 KIE。该方法显示了广泛的底物范围和官能团耐受性。使用这种开发的策略实现了各种重要分子和药物的许多后期硼化。硼化化合物进一步转化为更有价值的官能团。此外,利用单硼化化合物的 B-N 分子内相互作用的优势,开发了一种操作简单的方法,用于选择性二硼化 2-苯氧基吡啶和许多官能化芳烃。此外,还展示了从硼化产物中去除吡啶基导向基团以实现邻硼化苯酚以及用于制备 1,2-二硼化苯的
Ruthenium(II)-Catalyzed CH Alkenylations of Phenols with Removable Directing Groups
作者:Wenbo Ma、Lutz Ackermann
DOI:10.1002/chem.201301988
日期:2013.10.4
Cationic ruthenium(II) complexes enabled oxidativealkenylations of phenols bearing easily cleavable directing groups. The optimized catalytic system allowed twofold CH bond activations with excellent chemo‐, site‐, and diastereoselectivities. The double CH functionalization process proceeded efficiently in an aerobic fashion under an atmosphere of ambient air. Detailed mechanistic studies were performed
The invention provides novel substituted carboxylic acid derivatives that bind to receptor as ligands of human peroxisome proliferator-activated receptor (PPAR) to activate it and exhibit potent triglyceride-lowering action, cholesterol-lowering action and blood glucose-lowering action, and processes for preparing them.
The invention relates to substituted carboxylic acid derivatives represented by a general formula (1),
their pharmaceutically acceptable salts and their hydrates, and processes for preparing them.