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

Èric Casals-Cruañas, Oscar F. Gonzalez-Belman, Pau Besalú-Sala, David James Nelson, Albert Poater

Research output: Contribution to journalArticle

8 Citations (Scopus)
7 Downloads (Pure)

Abstract

Dinuclear gold complexes and their use in catalysis have received significant recent attention, but there are few critical comparisons of mono- versus dual gold-catalysed pathways. 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)(η2-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 N-heterocyclic 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.
Original languageEnglish
Pages (from-to)1-10
Number of pages10
JournalOrganic and Biomolecular Chemistry
Early online date10 Jul 2017
DOIs
Publication statusE-pub ahead of print - 10 Jul 2017

Fingerprint

Alkynes
alkynes
Catalysis
Gold
catalysis
gold
alcohols
Alcohols
Alkenes
carbenes
Entropy
attack
alkenes
Density functional theory
Anions
Enthalpy
counters
Theoretical Models
enthalpy
entropy

Keywords

  • hydroalkoxylation
  • hydrophenoxylation
  • alkynes
  • entropy

Cite this

Casals-Cruañas, Èric ; Gonzalez-Belman, Oscar F. ; Besalú-Sala, Pau ; Nelson, David James ; Poater, Albert. / The preference for dual-gold(I) catalysis in the hydro(alkoxylation vs phenoxylation) of alkynes. In: Organic and Biomolecular Chemistry. 2017 ; pp. 1-10.
@article{defbad7bc9a04dd08b6ff77692c40ecd,
title = "The preference for dual-gold(I) catalysis in the hydro(alkoxylation vs phenoxylation) of alkynes",
abstract = "Dinuclear gold complexes and their use in catalysis have received significant recent attention, but there are few critical comparisons of mono- versus dual gold-catalysed pathways. 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)(η2-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 N-heterocyclic 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.",
keywords = "hydroalkoxylation, hydrophenoxylation, alkynes, entropy",
author = "{\`E}ric Casals-Crua{\~n}as and Gonzalez-Belman, {Oscar F.} and Pau Besal{\'u}-Sala and Nelson, {David James} and Albert Poater",
year = "2017",
month = "7",
day = "10",
doi = "10.1039/C7OB01457K",
language = "English",
pages = "1--10",
journal = "Organic and Biomolecular Chemistry",
issn = "1477-0520",

}

The preference for dual-gold(I) catalysis in the hydro(alkoxylation vs phenoxylation) of alkynes. / Casals-Cruañas, Èric; Gonzalez-Belman, Oscar F.; Besalú-Sala, Pau; Nelson, David James; Poater, Albert.

In: Organic and Biomolecular Chemistry, 10.07.2017, p. 1-10.

Research output: Contribution to journalArticle

TY - JOUR

T1 - The preference for dual-gold(I) catalysis in the hydro(alkoxylation vs phenoxylation) of alkynes

AU - Casals-Cruañas, Èric

AU - Gonzalez-Belman, Oscar F.

AU - Besalú-Sala, Pau

AU - Nelson, David James

AU - Poater, Albert

PY - 2017/7/10

Y1 - 2017/7/10

N2 - Dinuclear gold complexes and their use in catalysis have received significant recent attention, but there are few critical comparisons of mono- versus dual gold-catalysed pathways. 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)(η2-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 N-heterocyclic 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.

AB - Dinuclear gold complexes and their use in catalysis have received significant recent attention, but there are few critical comparisons of mono- versus dual gold-catalysed pathways. 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)(η2-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 N-heterocyclic 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.

KW - hydroalkoxylation

KW - hydrophenoxylation

KW - alkynes

KW - entropy

UR - http://pubs.rsc.org/en/journals/journalissues/ob

U2 - 10.1039/C7OB01457K

DO - 10.1039/C7OB01457K

M3 - Article

SP - 1

EP - 10

JO - Organic and Biomolecular Chemistry

JF - Organic and Biomolecular Chemistry

SN - 1477-0520

ER -