Ortho-Functionalization of 2-Phenoxypyrimidines via Palladium-Catalyzed C−H Bond Activation
作者:Shaojin Gu、Chao Chen、Wanzhi Chen
DOI:10.1021/jo901316b
日期:2009.9.18
The palladium-catalyzeddirect acetoxylation and arylation of 2-aryloxypyrimidine has been described. The aromatic C−H bonds may be functionalized in moderate to excellent yields providing a facile method for the synthesis of phenol derivatives, which show antimycobacterial and herbicidal activities.
Rhodium-catalyzed <i>ortho</i>-heteroarylation of phenols: directing group-enabled switching of the electronic bias for heteroaromatic coupling partner
作者:Yimin Wu、Wei Li、Linfeng Jiang、Luoqiang Zhang、Jingbo Lan、Jingsong You
DOI:10.1039/c8sc02529k
日期:——
The directedoxidative C–H/C–H cross-coupling reactions between a functionalized arene and a heteroarene typically exhibit an electronic bias for the heteroaromatic coupling partner. Disclosed herein is a conception of directing group enabled-switching of the electronic bias for coupling partner from the electron-deficient to electron-rich heteroarene, demonstrating that the modification of the directing
Intermolecular CH acyloxylations of phenols with removable directing groups were accomplished with a versatile rutheniumcatalyst. Specifically, a cationicruthenium(II) complex, formed in situ, enabled the chemoselective CH oxygenations of a broad range of substrates. The catalyst proved tolerant of synthetically valuable functional groups, and the substrate scope included both (hetero)aromatic
Electrochemical Intramolecular CH Amination: Synthesis of Benzoxazoles and Benzothiazoles
作者:Tatsuya Morofuji、Akihiro Shimizu、Jun‐ichi Yoshida
DOI:10.1002/chem.201406398
日期:2015.2.16
A new method for metal‐free intramolecularCHamination has been developed. Electrochemical oxidation of 2‐pyrimidyloxybenzenes and 2‐pyrimidylthiobenzenes, which can be easily prepared from phenols and thiophenols, respectively, followed by the treatment of the resulting pyrimidinium ions with piperidine gives 2‐aminobenzoxazoles and 2‐aminobenzothiazoles, respectively.
Ortho C-H allenylation of electron-rich benzene derivatives with propargylic alcohol derivatives has been a challenge, due to their great innate tendency toward a para C-H allenylation via an SN2'-type substitution process. Here, we described a Ru(II)-catalyzed regioselective ortho C-H allenylation of electron-rich aniline and phenol derivatives, which allows the previously challenging synthesis of a