Practical and Selective sp
<sup>3</sup>
C−H Bond Chlorination via Aminium Radicals
作者:Alastair J. McMillan、Martyna Sieńkowska、Piero Di Lorenzo、Gemma K. Gransbury、Nicholas F. Chilton、Michela Salamone、Alessandro Ruffoni、Massimo Bietti、Daniele Leonori
DOI:10.1002/anie.202100030
日期:2021.3.22
also the fine‐tuning of physicochemical and biological properties of drugs, agrochemicals and polymers. We report here a general and practical photochemical strategy enabling the site‐selective chlorination of sp3 C−H bonds. This process exploits the ability of protonated N‐chloroamines to serve as aminium radical precursors and also radical chlorinatingagents. Upon photochemical initiation, an efficient
Visible Light-Promoted Aliphatic C–H Arylation Using Selectfluor as a Hydrogen Atom Transfer Reagent
作者:Hong Zhao、Jian Jin
DOI:10.1021/acs.orglett.9b01635
日期:2019.8.16
A mild, practical method for direct arylation of unactivated C(sp3)–H bonds with heteroarenes has been achieved via photochemistry. Selectfluor is used as a hydrogen atom transfer reagent under visible light irradiation. A diverse range of chemical feedstocks, such as alkanes, ketones, esters, and ethers, and complex molecules readily undergo intermolecular C(sp3)–C(sp2) bond formation. Moreover, a
Photoredox-Mediated Minisci-type Alkylation of <i>N</i>-Heteroarenes with Alkanes with High Methylene Selectivity
作者:Guo-Xing Li、Xiafei Hu、Gang He、Gong Chen
DOI:10.1021/acscatal.8b04079
日期:2018.12.7
We report a highly efficient and chemoselective Minisci-type alkylation reaction of N-heteroarenes with alkanes under the reagent control of a hypervalent iodine oxidant PFBI-OH. In addition to the high reactivity, PFBI-OH demonstrated a high steric sensitivity for H abstraction of alkanes. This reaction is selective for more sterically accessible secondary C–H bonds over weaker tertiary C–H bonds
Synergistic Activation of Amides and Hydrocarbons for Direct C(sp
<sup>3</sup>
)–H Acylation Enabled by Metallaphotoredox Catalysis
作者:Geun Seok Lee、Joonghee Won、Seulhui Choi、Mu‐Hyun Baik、Soon Hyeok Hong
DOI:10.1002/anie.202004441
日期:2020.9.21
amides as stable and readily accessible acyl surrogates. N‐acylsuccinimides served as efficient acyl reagents for the streamlined synthesis of synthetically useful ketones from simple C(sp3)−H substrates. Detailed mechanistic investigations using both computational and experimental mechanistic studies were performed to construct a detailed and complete catalytic cycle. The origin of the superior reactivity
Rapid “Mix-and-Stir” Preparation of Well-Defined Palladium on Carbon Catalysts for Efficient Practical Use
作者:Sergey A. Yakukhnov、Evgeniy O. Pentsak、Konstantin I. Galkin、Roman M. Mironenko、Vladimir A. Drozdov、Vladimir A. Likholobov、Valentine P. Ananikov
DOI:10.1002/cctc.201700738
日期:2018.4.24
A facile direct deposition approach for the preparation of recyclable Pd/C catalysts simply by stirring a solution of tris(dibenzylideneacetone)dipalladium(0) with a suitable carbon material was evaluated. An extraordinarily rapid catalyst preparation procedure (<5 min) under mild conditions and its excellent performance in cross‐coupling and hydrogenation reactions were demonstrated. The key point
评价了一种简单的直接沉积方法,该方法用于简单地通过搅拌三(二亚苄基丙酮)二钯(0)与合适的碳材料的溶液来制备可回收的Pd / C催化剂。证明了在温和条件下非常快速的催化剂制备程序(<5分钟)及其在交叉偶联和加氢反应中的优异性能。催化剂设计的关键是将Pd 0中心直接沉积在高度可及的表面积上,避免出现不确定的Pd II / Pd 0状态。