Regio- and Chemoselective CH Chlorination/Bromination of Electron-Deficient Arenes by Weak Coordination and Study of Relative Directing-Group Abilities
作者:Xiuyun Sun、Gang Shan、Yonghui Sun、Yu Rao
DOI:10.1002/anie.201300176
日期:2013.4.15
It's all relative: A practical and efficient PdII‐catalyzed regio‐ and chemoselectivechlorination/bromination has been developed for the facile synthesis of a broad range of aromatic chlorides. The reaction demonstrates excellent reactivity, good functional‐group tolerance, and high yields. A preliminary study was conducted to evaluate relative directing‐group abilities of various functionalities
Pd-Catalyzed CH Oxygenation with TFA/TFAA: Expedient Access to Oxygen-Containing Heterocycles and Late-Stage Drug Modification
作者:Gang Shan、Xinglin Yang、Linlin Ma、Yu Rao
DOI:10.1002/anie.201207458
日期:2012.12.21
Acid brings the oxygen: A generalmethod for palladium‐catalyzed CH oxygenation has been developed for the facilesynthesis of a wide range of functionalized phenols with readily available aryl ketones, benzoates, benzamides, acetanilides, and sulfonamides. A trifluoroacetic acid/trifluoroacetic acid anhydride solvent system serves as the oxygen source and is the critical factor for CH activation
Pd(II)-Catalyzed Direct <i>ortho</i>-C–H Acylation of Aromatic Ketones by Oxidative Decarboxylation of α-Oxocarboxylic Acids
作者:Pui-Yiu Lee、Peiwen Liang、Wing-Yiu Yu
DOI:10.1021/acs.orglett.7b00677
日期:2017.4.21
A Pd-catalyzed decarboxylative acylation of aromaticketones with α-oxocarboxylic acids was developed, and 1,2-diacylbenzenes were formed in up to 90% yield with excellent ortho-selectivity. This work demonstrates the first successful attempt to direct C–H acylation of aromaticketones without the need for prederivatization to imines. The acylation reaction was inhibited by radical scavengers such
boron‐cluster‐based persistent phosphors obtained by linking a σ‐aromatic carboranyl cage to the π system of a carbazolyl group. The carboranes were found to promote intersystem crossing from a singlet to a triplet state. The rigid boron cluster was able to stabilize the ultralong triplet excitons through multiple nonclassical hydrogen bonds, such as B−H⋅⋅⋅π interactions, thus leading to a long lifetime of up to
Palladium-Catalyzed Intermolecular Directed C−H Amidation of Aromatic Ketones
作者:Bin Xiao、Tian-Jun Gong、Jun Xu、Zhao-Jing Liu、Lei Liu
DOI:10.1021/ja108450m
日期:2011.2.9
Pd-catalyzed directed ortho C-H amidation of aromatic ketones with both sulfonamides and amides has been accomplished. The use of an electron-deficient Pd complex, Pd(OTf)(2), is crucial for the success of this transformation. Some key intermediates of the reaction, that is, the cyclopalladation complexes of ketones, have been characterized by X-ray crystallography. Experimental analysis of these palladacycles