Weak Coordination Promoted Regioselective Oxidative Coupling Reaction for 2,2′-Difunctional Biaryl Synthesis in Hexafluoro-2-propanol
作者:Chao Zhang、Yu Rao
DOI:10.1021/acs.orglett.5b02115
日期:2015.9.18
An unprecedented weak coordination promoted dehydrogenative cross-coupling reaction has been developed by palladium catalysis, which provides a convenient access to a wide range of 2,2′-difunctional biaryls from easily accessible substrates. Both HFIP solvent and oxidants serve as the critical factors in this new reaction. A plausible mechanism involving Pd(II)/Pd(IV) is proposed. The reaction demonstrates
Copper
<scp>porphyrin‐catalyzed</scp>
C(sp
<sup>2</sup>
)
<b>—</b>
O bond construction via coupling phenols with formamides
作者:Shuang Yang、Xiao‐Yan Chen、Ming‐Feng Xiong、Hao Zhang、Lei Shi、Dong‐Zi Lin、Hai‐Yang Liu
DOI:10.1002/jccs.202100046
日期:2021.8
construction of C(sp2)—Obond via coupling formamides with phenols was achieved firstly. A broad range of substrates afforded various carbamates in moderate to good yields with good functional group tolerance at low catalyst loading. Intermolecular competing kinetic isotope effect experiment indicated that the generation of formamide radical is the rate-determining step of current cross-dehydrogenative coupling
Room-temperature Pd-catalyzed C–H chlorination by weak coordination: one-pot synthesis of 2-chlorophenols with excellent regioselectivity
作者:Xiuyun Sun、Yonghui Sun、Chao Zhang、Yu Rao
DOI:10.1039/c3cc47431c
日期:——
A room-temperature Pd(II)-catalyzed regioselective chlorination reaction has been developed for a facile one-pot synthesis of a broad range of 2-chlorophenols. The reaction demonstrates an excellent regioselectivity and reactivity for CâH chlorination. This reaction represents one of the rare examples of mild CâH functionalization at ambient temperature.
Pd(II)-Catalyzed C−H Activation/Aryl−Aryl Coupling of Phenol Esters
作者:Bin Xiao、Yao Fu、Jun Xu、Tian-Jun Gong、Jian-Jun Dai、Jun Yi、Lei Liu
DOI:10.1021/ja909818n
日期:2010.1.20
reactions have been well-known, Pd(II) insertion into C-H bonds promoted by coordination of an oxygen-only group to the palladium remains rather rare. In the present study, the first cyclopalladation complex formed from a simple phenol ester was characterized by X-ray crystallography. A promising protocol for the ortho C-H activation/aryl-aryl coupling of phenol esters that was not sensitive to moisture
尽管含氮基团导向的环钯化反应已广为人知,但通过仅含氧的基团与钯的配位促进 Pd(II) 插入 CH 键的情况仍然相当罕见。在本研究中,第一个由简单苯酚酯形成的环钯化配合物通过 X 射线晶体学表征。然后建立了对水分或空气不敏感的苯酚酯邻位 CH 活化/芳基-芳基偶联的有前途的方案。该反应的效用已被证明可用于合成有用的苯酚衍生物。
Palladium-Catalyzed <i>Ortho</i>-Arylation of <i>O</i>-Phenylcarbamates with Simple Arenes and Sodium Persulfate
作者:Xiaodan Zhao、Charles S. Yeung、Vy M. Dong
DOI:10.1021/ja100783c
日期:2010.4.28
reactive C-H bonds are present on the O-phenylcarbamate, selective diarylation can be achieved via quadruple C-Hbond functionalization. This work represents a rare example of using O-carbamates as directing groups for catalytic C-Hbondactivation. Additionally, a palladacycle obtained from an O-phenylcarbamate was prepared and fully characterized. This trifluoroacetate-bridged bimetallic Pd complex