Oxidative Addition of Alkenyl and Alkynyl Iodides to a Au
<sup>I</sup>
Complex
作者:Jamie A. Cadge、Hazel A. Sparkes、John F. Bower、Christopher A. Russell
DOI:10.1002/anie.202000473
日期:2020.4.16
intermolecular oxidative addition of alkenyl and alkynyl iodides to AuI are reported. Using a 5,5'-difluoro-2,2'-bipyridyl ligated complex, oxidative addition of geometrically defined alkenyl iodides occurs readily, reversibly and stereospecifically to give alkenyl-AuIII complexes. Conversely, reversible alkynyl iodide oxidative addition generates bimetallic complexes containing both AuIII and AuI centers. Stoichiometric
“Anti-Michael addition” of Grignard reagents to sulfonylacetylenes: synthesis of alkynes
作者:Francisco Esteban、Lazhar Boughani、José L. García Ruano、Alberto Fraile、José Alemán
DOI:10.1039/c7ob00783c
日期:——
In this work, the addition of Grignardreagents to arylsulfonylacetylenes, which undergoes an “anti-Michael addition”, resulting in their alkynylation under very mild conditions is described. The simplicity of the experimental procedure and the functional group tolerance are the main features of this methodology. This is an important advantage over the use of organolithium at −78 °C that we previously
Visible-light-activated copper(<scp>i</scp>) catalyzed oxidative C<sub>sp</sub>–C<sub>sp</sub> cross-coupling reaction: efficient synthesis of unsymmetrical conjugated diynes without ligands and base
A novel visible-light-promoted copper-catalysed process for highly selective Csp-Csp cross-coupling reaction of terminal alkynes at room temperature is described. The current photochemical method is simple, high functional group compatible, and...
Strategy to isolate ionic gold sites on silica surface: Increasing their efficiency as catalyst for the formation of 1,3-diynes
作者:Cezar A. Didó、Felipe L. Coelho、Maurício B. Closs、Monique Deon、Flavio Horowitz、Fabiano Bernardi、Paulo H. Schneider、Edilson V. Benvenutti
DOI:10.1016/j.apcata.2020.117444
日期:2020.3
strategy is presented to obtain an efficient heterogeneous goldcatalyst constituted by isolated ionic gold sites, which is known to be effective in alkyne coupling reaction. The procedure is based on a significant difference between offered gold amount and available adsorbent sites on the support, ensuring the formation of very active isolated gold ion sites. In order to achieve this purpose, mesoporous
Copper(II)/Palladium(II) catalysed highly selective cross-coupling of terminal alkynes in supercritical carbon dioxide
作者:Yunlong Wang、Quanling Suo、Limin Han、Linlin Guo、Yaqi Wang、Fawang Li
DOI:10.1016/j.tet.2018.02.060
日期:2018.4
An efficient protocol for the synthesis of unsymmetrical 1,3-diynes was developed using supercriticalcarbondioxide (ScCO2) as the solvent. The direct coupling of two different terminal alkynes is catalysed by a bimetallic catalyst, CuCl2·2H2O/Pd(NH3)4Cl2·H2O, in the presence of the base tetramethylethylenediamine (TMEDA) and O2. In pure ScCO2, our bimetallic catalytic system maintains high activity