Thermodynamics of N-Heterocyclic Carbene Dimerization: The Balance of Sterics and Electronics

Poater, Albert; Ragone, Francesco; Giudice, Simona; Costabile, Chiara; Dorta, Reto; Nolan, Steven P.; Cavallo, Luigi

doi:10.1021/om8001119

Cited by 218 publications

(157 citation statements)

References 21 publications

Supporting

Mentioning

150

Contrasting

Unclassified

Order By: Relevance

“…77,78 By using SambVca (version 2), it is possible to analyse and visualise the first coordination sphere around the metal where the catalysis takes place. [79][80][81] The quadrants around gold in the IMe and IPr complexes were plotted as steric contour maps (Figure 4). It is evident from Figure 4 that for these two Au complexes, species bearing IPr present significantly more steric bulk.…”

Section: Digold Catalysismentioning

confidence: 99%

The preference for dual-gold(i) catalysis in the hydro(alkoxylation vs. phenoxylation) of alkynes

et al. 2017

Self Cite

View full text Add to dashboard Cite

This version is available at https://strathprints.strath.ac.uk/61289/ Strathprints is designed to allow users to access the research output of the University of Strathclyde. Unless otherwise explicitly stated on the manuscript, Copyright © and Moral Rights for the papers on this site are retained by the individual authors and/or other copyright owners. Please check the manuscript for details of any other licences that may have been applied. You may not engage in further distribution of the material for any profitmaking activities or any commercial gain. You may freely distribute both the url (https://strathprints.strath.ac.uk/) and the content of this paper for research or private study, educational, or not-for-profit purposes without prior permission or charge.Any correspondence concerning this service should be sent to the Strathprints administrator: strathprints@strath.ac.ukThe Strathprints institutional repository (https://strathprints.strath.ac.uk) is a digital archive of University of Strathclyde research outputs. It has been developed to disseminate open access research outputs, expose data about those outputs, and enable the management and persistent access to Strathclyde's intellectual output. Herein we study the hydroalkoxylation and hydrophenoxylation of alkynes using density functional theory calculations, and compare two possible mechanisms that have been proposed previously on the basis of theoretical and experimental studies, which unravel different preferences because of both the nature of the alkyne and alcohol, as well as the non-innocent role of the counter-anion of the dual gold based catalyst. Entropy is found to have a significant effect, rendering the nucleophilic attack of the monoaurated intermediate [Au(L)(η 2 -alkyne)] + difficult both kinetically and thermodynamically; this mechanism cannot easily form only the trans-alkene product that is observed experimentally. Instead, reaction via a dual gold catalysed mechanism presents much lower barriers. In addition, for the sake of direct comparison with recent results by Belanzoni, Zuccaccia, oversimplification of the Nheterocyclic carbene (NHC) ligand in the calculations might decrease the enthalpy barrier and lead to results that are not directly applicable to experiment. Moreover, the alkylic or arylic nature of the alkyne and/or alcohol is also tested. ORGANIC & BIOMOLECULAR CHEMISTRY ARTICLE

show abstract

Section: Digold Catalysismentioning

confidence: 99%

The preference for dual-gold(i) catalysis in the hydro(alkoxylation vs. phenoxylation) of alkynes

et al. 2017

Self Cite

View full text Add to dashboard Cite

show abstract

“…Steric and electronic effects in the dimerization process were discussed. [36] The stronger tendency to dimerize of saturated NHCs, compared with unsaturated ones, was correlated to electronic effects [37,38]. used [33].…”

Section: Nhc Stabilitymentioning

confidence: 99%

Advances in the Knowledge of N-Heterocyclic Carbenes Properties. The Backing of the Electrochemical Investigation

2016

View full text Add to dashboard Cite

“…[7][8][9] In catalysis, work in the last decade has shown that monodentate NHCs with bulky, arylsubstituted side chains are the overall most successful design. As such, 2,4,6-mesityl-substituted IMes and 2,6-isopropylphenyl-substituted IPr and their saturated imidazolin-2-ylidene counterparts (SIMes and SIPr) still remain the only ligands that represent a truly viable alternative to phosphines, in terms of both versatility and reactivity.…”

Section: Introductionmentioning

confidence: 99%

The effect of substituents on the syn-anti conformer ratio in naphthyl-based imidazolinium salts and their corresponding N-heterocyclic carbenes

Gatti¹,

Wu²,

Drinkel³

et al. 2010

Arkivoc

Self Cite

View full text Add to dashboard Cite

Eight new N-heterocyclic carbenes (NHCs) featuring substituted naphthyl side chains were synthesized. These molecules are present in solution as a stable mixture of anti and syn conformers. Through careful tuning of the substituents on position 2 and 2,7 of the naphthyl moieties, it was possible to synthesize molecules that display a strong preference for the anti conformation (up to 95:5). This will greatly facilitate their optimized use as single isomeric ligands in metal-catalysis and as organocatalysts.

show abstract

Thermodynamics of N-Heterocyclic Carbene Dimerization: The Balance of Sterics and Electronics

Cited by 218 publications

References 21 publications

The preference for dual-gold(i) catalysis in the hydro(alkoxylation vs. phenoxylation) of alkynes

The preference for dual-gold(i) catalysis in the hydro(alkoxylation vs. phenoxylation) of alkynes

Advances in the Knowledge of N-Heterocyclic Carbenes Properties. The Backing of the Electrochemical Investigation

The effect of substituents on the syn-anti conformer ratio in naphthyl-based imidazolinium salts and their corresponding N-heterocyclic carbenes

Contact Info

Product

Resources

About