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
Cobalt-catalyzed C(sp<sup>3</sup>)–H/C(sp<sup>2</sup>)–H oxidative coupling between alkanes and benzamides
作者:Shuangjie Li、Bao Wang、Guangyu Dong、Chunpu Li、Hong Liu
DOI:10.1039/c8ra01377b
日期:——
A direct cobalt-catalyzed oxidativecoupling between C(sp2)–H in unactivated benzamides and C(sp3)–H in simple alkanes, ethers and toluene derivatives was explored. This protocol achieves direct C–C formation without using alkyl or aryl halide surrogates and exhibits high practicality with ample substrate scope. The method provides a new way to construct linear and five- or six-membered ring moieties
A sustainable and simple catalytic system for direct alkynylation of C(sp<sup>2</sup>)–H bonds with low nickel loadings
作者:Yue-Jin Liu、Yan-Hua Liu、Sheng-Yi Yan、Bing-Feng Shi
DOI:10.1039/c5cc01163a
日期:——
A sustainable and simple catalytic system for the atom-economical alkynylation of benzamides with low nickel loadings is described. No organic or metallic oxidants and expensive ligands are required. A broad range of benzamides and bromoalkynes bearing various synthetically useful functional groups are compatible with this reaction. The versatility of this operationally simple protocol has been further