The catalytic dearomatization of pyridines, accessing medicinally relevant N-heterocycles, is of high interest. Currently direct, dearomative strategies rely generally on reduction or nucleophilic addition, thus limiting the architecture of the dearomatized products to a six-membered ring. We herein introduce a catalytic, dearomative cycloaddition reaction with pyridines using photoinduced energy transfer
Synthesis of Spiro-dihydroquinoline and Octahydrophenanthrene Derivatives via Palladium-Catalyzed Intramolecular Oxidative Arylation
作者:Zhong-Lin Zang、Shuklachary Karnakanti、Sheng Zhao、Ping Hu、Zhen Wang、Pan-Lin Shao、Yun He
DOI:10.1021/acs.orglett.7b00228
日期:2017.3.17
A method for intramolecular sp2 C–H oxidative arylation of unactivated cyclic olefins has been developed to access spiro-dihydroquinoline and octahydrophenanthrene derivatives in a straightforward and efficient manner. Bearing picolinamide as a directing group, the alkenyl anilines cyclized to afford spiro-dihydroquinolines in moderate to excellent yields via direct oxidative arylation, while the alkenyl
Pd-Catalyzed Remote Site-Selective and Stereoselective C(Alkenyl)–H Alkenylation of Unactivated Cycloalkenes
作者:Chun-Li Mao、Sheng Zhao、Zhong-Lin Zang、Lin Xiao、Cheng-He Zhou、Yun He、Gui-Xin Cai
DOI:10.1021/acs.joc.9b02797
日期:2020.1.17
A palladium-catalyzed alkenylation involving remote δ-position C(alkenyl)-H activation of cycloalkenes reacting with electron-deficient alkenes is described. This method features excellent site selectivity and stereoselectivity to efficiently afford only E-selective highly substituted 1,3-diene derivatives with extra-ligand-free and good functional group tolerance including estrone and free N-H tryptamine
Catalytic Multisite-Selective Acetoxylation Reactions at sp<sup>2</sup> vs sp<sup>3</sup> C–H Bonds in Cyclic Olefins
作者:Zhong-Lin Zang、Sheng Zhao、Shuklachary Karnakanti、Cheng-Lin Liu、Pan-Lin Shao、Yun He
DOI:10.1021/acs.orglett.6b02458
日期:2016.10.7
The first Pd-catalyzed multisite-selective acetoxylation reactions are disclosed at an unactivated alkene sp2 C–H bond versus secondary allylic sp3 C–H bond in cyclic olefins via the modulation of directing groups. The different directing groups overcome the key challenge in differentiating C–H bonds and provide a new controlling approach for site-specific C–H activation. A wide variety of substrates