A novel, efficient, and mild synthetic route for the preparation of 2-aminopyridines via ruthenium-mediated [2 + 2 + 2] cycloaddition of α,ω-diynes and cyanamides has been developed. This atom-economical catalytic process demonstrated remarkable regioselectivities to access pyridine derivatives of high synthetic utility.
Cobalt-Catalyzed Cyclization/Hydroboration of 1,6-Diynes with Pinacolborane
作者:Qiang Huang、Meng-Yang Hu、Shou-Fei Zhu
DOI:10.1021/acs.orglett.9b02873
日期:2019.10.4
Herein, we report a protocol for cyclization/hydroboration of 1,6-diynes with pinacolborane using a cobalt catalyst generated in situ from a Co(II)-phenanthroline complex, tetrabutylammonium fluoride, and pinacolborane. This protocol, which features good functional group tolerance, a broad substrate scope, and excellent stereoselectivity, enables the synthesis of useful cyclic 1,3-dienylboron compounds
Cobalt-Catalyzed gem-Cross-Dimerization of Terminal Alkynes
作者:Jia-Feng Chen、Changkun Li
DOI:10.1021/acscatal.9b05078
日期:2020.3.20
Transition-metal-catalyzed dimerization of two different terminalalkynes provides an atom-economic synthesis of valuable conjugated 1,3-enynes. Despite many catalyst systems developed, the state-of-the-art solutions are still limited to special alkynes. A practical catalyst, which could be used to cross-dimerize general aryl alkynes and aliphatic alkynes, is still highly desired. Herein we present
dihydroazepine rings by a cascadereaction encompassing a rhodium-catalyzed cycloisomerization of 1,5-bisallenes and a [4+2] cycloaddition. This transition metal-catalyzed cascadereaction provides a versatile and step-economical approach to the synthesis of 6,7-membered polyheterocyclic fullerene adducts. Electrochemical characterization of the products obtained ventures their application in organic and perovskite
据报道,一种合成方法通过包括铑催化的 1,5-双丙二烯环异构化和 [4+2] 环加成的级联反应,用二氢氮杂环将C 60和 C 70富勒烯官能化。这种过渡金属催化的级联反应为合成 6,7 元多杂环富勒烯加合物提供了一种通用且步骤经济的方法。获得的产品的电化学表征冒险它们在有机和钙钛矿光伏器件中的应用。
Cyclization/Hydrosilylation of Functionalized Diynes Catalyzed by a Cationic Platinum Phenanthroline Complex
作者:James W. Madine、Xiang Wang、Ross A. Widenhoefer
DOI:10.1021/ol006901u
日期:2001.2.1
[figure: see text] A 1:1 mixture of the platinum phenanthroline complex (phen)PtMe2 and B(C6F5)3 catalyzed the cyclization/hydrosilylation of functionalized 1,6- and 1,7-diynes to form silylated 1,2-dialkylidenecycloalkanes in good yield and with high Z-selectivity.