المؤلفون: Nahra, Fady, Patrick, Scott R, Bello, Davide, Brill, Marcel, Obled, Alan, Cordes, David B, Slawin, Alexandra M Z, O'Hagan, David, Nolan, Steven P

المصدر: Chemcatchem

مصطلحات موضوعية: carbenes, bifluorides, hydrofluorination, gold, alkynes, Communications

الوصف: We report the synthesis of nine new N-heterocyclic carbene gold bifluoride complexes starting from the corresponding N-heterocyclic carbene gold hydroxides. A new methodology to access N,N′-bis(2,6-diisopropylphenyl)imidazol-2-ylidene gold(I) fluoride starting from N,N′-bis(2,6-diisopropylphenyl)imidazol-2-ylidene gold(I) hydroxide and readily available potassium bifluoride is also reported. These gold bifluorides were shown to be efficient catalysts in the hydrofluorination of symmetrical and unsymmetrical alkynes, thus affording fluorinated stilbene analogues and fluorovinyl thioethers in good to excellent yields with high stereo- and regioselectivity. The method is exploited further to access a fluorinated combretastatin analogue selectively in two steps starting from commercially available reagents.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=pmid________::a335ce5a37d68cf1452529f22fc75725Test
http://europepmc.org/articles/PMC4515107Test

المؤلفون: Izquierdo, Frédéric, Zinser, Caroline, Minenkov, Yury, Cordes, David B., Slawin, Alexandra M. Z., Cavallo, Luigi, Nahra, Fady, Cazin, Catherine S. J., Nolan, Steven P.

المصدر: ChemCatChem; 2/7/2018, Vol. 10 Issue 3, p601-611, 11p

مصطلحات موضوعية: CATALYTIC activity, HALOGENATION, LIGANDS (Chemistry), CATALYSTS, PALLADIUM

مستخلص: Abstract: The influence of C^4,5‐halogenation on palladium N‐heterocyclic carbene complexes and their activity in the Suzuki–Miyaura reaction were investigated. Two [Pd(NHC)(cin)Cl] complexes bearing IPr^Cl and IPr^Br ligands (IPr=1,3‐bis(2,6‐diisopropyl‐phenyl)imidazol‐2‐ylidene; cin=cinnamyl) were synthesized. After determining the electronic and steric properties of these ligands, their properties were compared to those of [Pd(IPr) (cin)Cl]. The three palladium complexes were studied by using DFT calculations to delineate their behavior in the activation step leading to the putative 12‐electron active catalyst. Experimentally, their catalytic activity in the Suzuki–Miyaura reaction involving a wide range of coupling partners (30 entries) at low catalyst loading was studied. [ABSTRACT FROM AUTHOR]

: Copyright of ChemCatChem is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

المؤلفون: Brill, Marcel, Nahra, Fady, Gómez‐Herrera, Alberto, Zinser, Caroline, Cordes, David B., Slawin, Alexandra M. Z., Nolan, Steven P.

المصدر: ChemCatChem; 1/9/2017, Vol. 9 Issue 1, p117-120, 4p

مصطلحات موضوعية: HETEROCYCLIC chemistry, PROTON transfer reactions, SULFURIC acid, ALKYNES, ORGANOMETALLIC chemistry

مستخلص: We have synthesized and characterized new gold-N-heterocyclic carbene (NHC) complexes derived from the deprotonation of mineral acids. The use of sulfuric acid was a particularly interesting case. These complexes were tested in known gold-catalyzed reactions, such as the hydration of alkynes and the Meyer-Schuster rearrangement. They proved to be highly efficient in both reactions. [ABSTRACT FROM AUTHOR]

: Copyright of ChemCatChem is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

المؤلفون: Nahra, Fady, Patrick, Scott R., Bello, Davide, Brill, Marcel, Obled, Alan, Cordes, David B., Slawin, Alexandra M. Z., O'Hagan, David, Nolan, Steven P.

المصدر: ChemCatChem; Jan2015, Vol. 7 Issue 2, p240-244, 5p

مصطلحات موضوعية: GOLD compound synthesis, ALKYNE synthesis, REGIOSELECTIVITY (Chemistry), IMIDAZOLES, CHEMICAL synthesis, FLUORINATION, CARBENE synthesis

مستخلص: We report the synthesis of nine new N-heterocyclic carbene gold bifluoride complexes starting from the corresponding N-heterocyclic carbene gold hydroxides. A new methodology to access N,N′-bis(2,6-diisopropylphenyl)imidazol-2-ylidene gold(I) fluoride starting from N,N′-bis(2,6-diisopropylphenyl)imidazol-2-ylidene gold(I) hydroxide and readily available potassium bifluoride is also reported. These gold bifluorides were shown to be efficient catalysts in the hydrofluorination of symmetrical and unsymmetrical alkynes, thus affording fluorinated stilbene analogues and fluorovinyl thioethers in good to excellent yields with high stereo- and regioselectivity. The method is exploited further to access a fluorinated combretastatin analogue selectively in two steps starting from commercially available reagents. [ABSTRACT FROM AUTHOR]

: Copyright of ChemCatChem is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)