Cobalt-Catalyzed C(sp<sup>2</sup>)−H Methylation by using Dicumyl Peroxide as both the Methylating Reagent and Hydrogen Acceptor
作者:Qun Li、Yanrong Li、Weipeng Hu、Renjian Hu、Guigen Li、Hongjian Lu
DOI:10.1002/chem.201602445
日期:2016.8.22
The first cobalt‐catalyzed direct methylation of a C(sp2)−H bond usingdicumylperoxide (DCP) as both the methylatingreagent and hydrogenacceptor has been established. The reaction proceeded without the use of any additives, and was proven to be applicable to various amides bearing a 2‐pyridinylisopropyl (PIP) directing group, providing an efficient access to o‐methyl aryl amides with high functional‐group
Cobalt-Catalyzed Secondary Alkylation of Arenes and Olefins with Alkyl Ethers through the Cleavage of C(sp<sup>2</sup>)–H and C(sp<sup>3</sup>)–O Bonds
作者:Xunqing Dong、Qun Li、Guigen Li、Hongjian Lu
DOI:10.1021/acs.joc.8b02197
日期:2018.11.2
A novel cobalt-catalyzed C–H alkylation of arenes and olefins is achieved with (pyridin-2-yl)isopropyl amine as an N,N-bidentate directing group. Different linear, branched, and cyclic alkyl ethers were used as practical secondary alkylating reagents through cleavage of C(sp3)–O bond, providing an efficient approach to the synthesis of verstile o-alkylated arylamides and tetrasubstituted acrylamides
Cobalt-Catalyzed Cross-Dehydrogenative Coupling Reaction between Unactivated C(sp<sup>2</sup>)–H and C(sp<sup>3</sup>)–H Bonds
作者:Qun Li、Weipeng Hu、Renjian Hu、Hongjian Lu、Guigen Li
DOI:10.1021/acs.orglett.7b02316
日期:2017.9.1
Catalytic oxidative cross-dehydrogenative coupling between unactivated C(sp2)–H and C(sp3)–H bonds is achieved by the cobalt-catalyzed o-alkylation reaction of aromatic carboxamides containing (pyridin-2-yl)isopropyl amine (PIP–NH2) as a N,N-bidentate directing group. Many different C(sp3)–H bonds in alkanes, toluene derivatives and even in the α-position of ethers and thioethers can be used as coupling
Nickel-Catalyzed <i>Ortho-</i>Arylation of Unactivated (Hetero)aryl C–H Bonds with Arylsilanes Using a Removable Auxiliary
作者:Sheng Zhao、Bin Liu、Bei-Bei Zhan、Wei-Dong Zhang、Bing-Feng Shi
DOI:10.1021/acs.orglett.6b02236
日期:2016.9.16
Ni(II)-catalyzed ortho-arylation of aromatic and heteroaromatic carboxamides with triethoxy(aryl)silanes assisted by a removable bidentate auxiliary is reported. This transformation features a broad substrate scope, good functional group tolerance, and compatibility with heterocyclic substrates. Compared to the well-established Ni(II)-catalyzed C–H arylation with ArX or aryliodonium salts via oxidative