High-Yielding, Versatile, and Practical [Rh(III)Cp*]-CatalyzedOrthoBromination and Iodination of Arenes
摘要:
We report a uniquely high-yielding, general, and practical ortho bromination and iodination reaction of different classes of aromatic compounds. This reaction occurs by Rh(III)-catalyzed C-H bond activation methodology and is therefore the first example of the application of this cationic catalyst for C-Br and C-I bond formation.
Deprotonative directed ortho cupration of aromatic/heteroaromatic C-H bond and subsequent oxidation with t-BuOOH furnished functionalized phenols in high yields with high regio- and chemoselectivity. DFT calculations revealed that this hydroxylation reaction proceeds via a copper (I → III → I) redox mechanism. Application of this reaction to aromatic C-H amination using BnONH2 efficiently afforded
芳族/杂芳族 CH 键的去质子定向邻铜化和随后用 t-BuOOH 氧化以高产率和高区域选择性和化学选择性提供官能化酚。DFT 计算表明,这种羟基化反应是通过铜 (I → III → I) 氧化还原机制进行的。将该反应应用于使用 BnONH2 的芳族 CH 胺化有效地提供了相应的伯苯胺。这些反应显示出广泛的范围和良好的官能团兼容性。还展示了这些转化的催化版本。
Palladium-Catalyzed Formylation of Arylzinc Reagents with<i>S</i>-Phenyl Thioformate
The first example of palladium-catalyzed direct formylation of arylzincreagents using S-phenyl thioformate is reported. The reaction proceeded undermildconditions, allowing high functional group tolerance. In addition, the developed formylation method was used to prepare deuterated and 13C-labeled aryl aldehydes from isotope-labeled S-phenyl thioformates. Moreover, this procedure was applied to
Electrochemical Synthesis of Biaryls via Oxidative Intramolecular Coupling of Tetra(hetero)arylborates
作者:Arif Music、Andreas N. Baumann、Philipp Spieß、Allan Plantefol、Thomas C. Jagau、Dorian Didier
DOI:10.1021/jacs.9b12300
日期:2020.3.4
scope, scalability and robustness of this unconventional catalyst-free transformation, leading to functional-ized biaryls and ultimately furnishing drug-like small molecules as well as late stage derivatization of natural compounds. In addition, the observed selectivity of the oxidative coupling reaction is related to the electronic structure of the TABs through quantum-chemical calculations and experimental
Lipshutz-type bis(amido)argentates for directed <i>ortho</i> argentation
作者:Noriyuki Tezuka、Keiichi Hirano、Andrew J. Peel、Andrew E. H. Wheatley、Kazunori Miyamoto、Masanobu Uchiyama
DOI:10.1039/c9sc06060j
日期:——
aromatic functionalization via unprecedented directed ortho argentation (DoAg). X-Ray crystallographic analysis showed that 3 takes a structure analogous to that of the corresponding Lipshutz cuprate. DoAg with this TMP-Ag-ate afforded multifunctional aromatics in high yields in processes that exhibited high chemoselectivity and compatibility with a wide range of functional groups. These included organometallics-
双(酰胺基)银盐(TMP)2 Ag(CN)Li 2(3,TMP-Ag-酸盐; TMP = 2,2,6,6-四甲基哌啶子基)被设计为通过空前的定向原位化学键进行化学选择性芳族官能化的工具(D o Ag)。X射线晶体学分析表明3具有与相应的Lipshutz铜酸盐类似的结构。d Ø具有这种TMP-Ag-酸酯的Ag在具有高化学选择性和与各种官能团相容性的工艺中,以高收率提供了多官能芳烃。这些包括对有机金属和过渡金属敏感的取代基,例如甲酯,醛,乙烯基,碘,(三氟甲磺酰基)氧基和硝基。白蚁类药物与各种亲电试剂显示出良好的反应性。硫属元素(S,Se和Te)的安装和偶氮偶合反应也有效进行。
Transition-Metal-Free Hydrogenation of Aryl Halides: From Alcohol to Aldehyde
作者:Hong-Xing Zheng、Xiang-Huan Shan、Jian-Ping Qu、Yan-Biao Kang
DOI:10.1021/acs.orglett.7b02399
日期:2017.10.6
A transition-metal- and catalyst-free hydrogenation of arylhalides, promoted by bases with either aldehydes or alcohols, is described. One equivalent of benzaldehyde affords an equal yield as that of 0.5 equiv of benzyl alcohol. The kinetic study reveals that the initial rate of PhCHO is much faster than that of BnOH, in the ratio of nearly 4:1. The radical trapping experiments indicate the radical