Regioselective palladium-catalyzed cross-coupling reactions in the synthesis of novel 2,3-disubstituted thiophene derivatives
作者:Raquel Pereira、Beatriz Iglesias、Angel R de Lera
DOI:10.1016/s0040-4020(01)00764-5
日期:2001.9
A reactivity optimization study of the palladium-catalyzed cross-coupling reactions of 2,3-dibromothiophene and organometallicreagents has been conducted. Regioselectivecoupling at the C2 position, accomplished most notably by Suzuki coupling, was combined with a Stille reaction at C3 using Fu's modification, to afford the 2,3-disubstituted thiophene derivatives.
We developed a technique mediated by visible light for the aerobic homocoupling of terminal alkynes to synthesize 1,3-conjugated diynes using a copper(I) chloride catalyst at room temperature. Compared with previously reported thermal processes, this photochemical method is simple, uses only mild reaction conditions, produces high yields and works well for substrates with electron-withdrawing groups
Efficient Copper(II) Acetate Catalyzed Homo- and Heterocoupling of Terminal Alkynes at Ambient Conditions
作者:Venkitasamy Kesavan、Kaluvu Balaraman
DOI:10.1055/s-0030-1258199
日期:2010.10
in quantitative yields using the copper(II) acetate catalyzed homocoupling of terminalalkynes in the presence of a stoichiometric amount of piperidine at 25 ˚C under aerobic conditions. We also accomplished facile syntheses of unsymmetric 1,3-diynes by heterocouplingterminalalkynes in very good yields under the reported reaction conditions. terminalalkynes - copper(II) acetate - piperidine - homocoupling
stereoselective synthesis of conjugated dienes was realized for the first time via Pd‐catalyzed alkoxycarbonylation of easily available 1,3‐diynes. Key to success is the utilization of the specific ligand 1,1′‐ferrocenediyl‐bis(tert‐butyl(pyridin‐2‐yl)phosphine) (L1), which allows this novel transformation to proceed at room temperature. A range of 1,2,3,4‐tetrasubstituted conjugated dienes are obtained in
Cobalt Catalyzed, Regioselective C(<i>sp</i><sup>2</sup>)–H Activation of Amides with 1,3-Diynes
作者:Subban Kathiravan、Ian A. Nicholls
DOI:10.1021/acs.orglett.7b02119
日期:2017.9.15
functional class of interest in a range of application areas, to form isoquinolinones—an important structural motif in a number of biologicallyactive substances—is presented. This versatile and inexpensive catalyst employs a covalently attached bidendate-directing group, 8-aminoquinoline. The template directs the C–H activation and facilitates the synthesis of a wide range of alkynylated heterocycles