<i>meta</i>
‐Nitration of Arenes Bearing
<i>ortho</i>
/
<i>para</i>
Directing Group(s) Using C−H Borylation
作者:Xuejing Li、Xingwang Deng、Anthony G. Coyne、Rajavel Srinivasan
DOI:10.1002/chem.201901633
日期:2019.6.18
of arenes bearing ortho/para directing group(s) using the iridium‐catalyzed C−H borylation reaction followed by a newly developed copper(II)‐catalyzed transformation of the crude aryl pinacol boronate esters into the corresponding nitroarenes in a one‐pot fashion. This protocol allows the synthesis of meta‐nitrated arenes that are tedious to prepare or require multistep synthesis using the existing
One-step conversions of 1,3-disubstituted benzenes to aryl boronates and 2,6-disubstituted pyridines to heteroaryl boronates are described. Microwave heating was used for all reactions. [(COD)Ir(μ-OMe)]2 and 4,4′-di-tert-butyl-2,2′-bipyridine were used as catalysts, in methyl tert-butyl ether. Acceleration of the rate of reaction was remarkable compared with that of same reaction under conventional heating conditions.
Reaction mixtures for silvlating arene substrates and methods of using such reaction mixtures to silyiate the arene substrates are provided. Exemplary reaction mixtures include the arene substrate, a liganded metal catalyst, a hydrogen acceptor and an organic solvent. The reaction conditions allow for diverse substituents on the arene substrate.
High-Turnover Aromatic C–H Borylation Catalyzed by POCOP-Type Pincer Complexes of Iridium
作者:Loren P. Press、Alex J. Kosanovich、Billy J. McCulloch、Oleg V. Ozerov
DOI:10.1021/jacs.6b03656
日期:2016.8.3
presence of stoichiometric quantities of sacrificial olefin, which is hydrogenated to consume the H2 equivalents generated in the borylation of C-H bonds with HBpin. Smaller olefins such as ethylene or 1-hexene were more advantageous to catalysis than sterically encumbered tert-butylethylene (TBE). Olefin hydroboration is a competing side reaction. The synthesis and isolation of multiple complexes potentially
已经证明了使用 Ir 的 POCOP 型钳形复合物对芳烃与 HBpin(pin = 频哪酸酯)的催化 CH 硼化,在某些情况下转换数超过 10 000。CH 活化的选择性基于空间偏好,并且在很大程度上反映了在其他 Ir 硼化催化剂中发现的选择性。(POCOP)Ir 系统中的催化取决于化学计量数量的牺牲烯烃的存在,该牺牲烯烃被氢化以消耗在 CH 键与 HBpin 的硼酸化中产生的 H2 等价物。较小的烯烃如乙烯或 1-己烯比空间阻碍的叔丁基乙烯 (TBE) 更有利于催化。烯烃硼氢化反应是一种竞争性副反应。可能与催化相关的多种复合物的合成和分离允许检查几个关键的基本反应。这些实验表明,催化中的 CH 活化步骤表面上涉及将芳族 CH 键氧化加成到三配位 (POCOP) Ir 物质上。烯烃对于获得这种 14 电子单价 Ir 中间体在机械上至关重要。此处 Ir(I) 处的 CH 活化与使用由中性双齿配体支持的最先进
Merging Iridium-Catalyzed C–H Borylations with Palladium-Catalyzed Cross-Couplings Using Triorganoindium Reagents
作者:Chathurika R. K. Jayasundara、José M. Gil-Negrete、Jose R. Montero Bastidas、Arzoo Chhabra、M. Montserrat Martínez、José Pérez Sestelo、Milton R. Smith、Robert E. Maleczka
DOI:10.1021/acs.joc.1c01978
日期:2022.1.7
borylated arenes furnished with alkyl, alkenyl, alkynyl, aryl, and heteroaryl functional groups is developed by merging Ir-catalyzed C–H borylations (CHB) with a chemoselective palladium-catalyzed cross-coupling of triorganoindiumreagents (Sarandeses–Sestelo coupling) with aryl halides bearing a boronic ester substituent. Using triorganoindiumcross-couplingreactions to introduce unsaturated moieties