Pyridyl Directed Catalyst-Free <i>trans</i>-Hydroboration of Internal Alkynes
作者:Kang Yuan、Naoya Suzuki、Soren K. Mellerup、Xiang Wang、Shigehiro Yamaguchi、Suning Wang
DOI:10.1021/acs.orglett.5b03698
日期:2016.2.19
trans-hydroboration of internal alkynes at room temperature with 9-BBN, producing five-membered BN-heterocycles. Contrary to conventional cis-hydroboration, we demonstrate that the introduction of a pyridyl group switches the stereoselectivity of the reaction. A hydride migration mechanism has been proposed and supported by DFT calculations for the trans-hydroboration. This new hydroboration approach
An anthraquinone-based Cu(I) cyclic trinuclear complex for photo-catalyzing C-C coupling reactions
作者:Yu-Mei Wang、Kai-Ming Mo、Xiao Luo、Ri-Qin Xia、Jing-Yi Song、Guo-Hong Ning、Dan Li
DOI:10.1007/s11426-023-1777-y
日期:2023.12
organic synthesis, yet remains highly challenging. In this article, an anthraquinone-based copper(I) cyclic trinuclear complex (1) was designed and it featured strong visible light absorption, high charge separation efficiency and photochemical properties. Complex 1 as a heterogeneous photocatalyst can efficiently catalyze homo-coupling of terminal alkynes and denitrification-oxidative coupling reaction
Enyne ring-closing metathesis on heteroaromatic cations
作者:Ana Núñez、Ana M. Cuadro、Julio Alvarez-Builla、Juan J. Vaquero
DOI:10.1039/b602420c
日期:——
Cationic heteroaromatic enynes have been employed as substrates in enyne ring-closing metathesis, under an atmosphere of ethylene and using the Hoveyda-Grubbs catalyst, for the first time; the reaction affords new 1-vinyl- and 2-vinyl-substituted 3,4-dihydroquinolizinium salts, useful precursors for biologically relevant cations based on the quinolinizium system.
Mild Pd/Cu-Catalyzed Sila-Sonogashira Coupling of (Hetero)aryl Bromides with (Hetero)arylethynylsilanes under PTC Conditions
作者:Fabio Bellina、Marco Lessi
DOI:10.1055/s-0031-1290601
日期:2012.3
The palladium/copper cocatalyzed sila-Sonogashira reaction of (hetero)arylethynysilanes with (hetero)aryl bromides in toluene and water at 40 ˚C under PTC conditions gave the required di(hetero)arylethynes in moderate to high yields. Activated, deactivated and ortho-substituted (hetero)aryl bromides are well tolerated. This protocol also allowed the preparation of symmetrical diarylethynes by double