Acid, silver, and solvent-free gold-catalyzed hydrophenoxylation of internal alkynes

Richard, Marcia E.; Fraccica, Daniel V.; Garcia, Kevin J.; Miller, Erica J.; Ciccarelli, Rosa M.; Holahan, Erin C.; Resh, Victoria L.; Shah, Aakash; Findeis, Peter M.; Stockland, Robert A.

doi:10.3762/bjoc.9.235

Cited by 12 publications

(10 citation statements)

References 26 publications

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“…Certain members of this family of organometallic complexes also exhibit interesting photophysical and biological properties, and therefore are extremely valuable materials . These compounds have also been used as substrates in cross‐coupling reactions, and have recently been shown as efficient pre‐catalysts in the acid‐ and silver‐free hydrophenoxylation of alkynes . Despite recent advances, their reactivity remains largely unexplored, presumably because of the methods used for their preparation, which can be viewed as operationally complex.…”

Section: Introductionmentioning

confidence: 99%

Simple Synthetic Routes to N‐Heterocyclic Carbene Gold(I)–Aryl Complexes: Expanded Scope and Reactivity

Tzouras

Saab

Janssens

et al. 2020

Chemistry A European J

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Thediscoveryofsustainable and scalablesynthetic protocols leading to gold-arylcompounds bearing N-heterocyclic carbene (NHC) ligandss parkeda ni nvestigationo f their reactivitya nd potential utility as organometallic synthons. The use of am ild base andg reen solvents provide access to these compounds, startingf rom widely available boronic acids and various [Au(NHC)Cl] complexes, with reactions taking place under air,a tr oom temperature and lead-ing to high yields with unprecedented ease. One compound, (N,N'-bis[2,6-(di-isopropyl)phenyl]imidazol-2-ylidene)(4-methoxyphenyl)gold, ([Au(IPr)(4-MeOC 6 H 4 )]), was synthesized on am ultigrams cale and used to gauge the reactivity of this class of compounds towards CÀH/NÀHb onds and with various acids, revealings imple pathways to gold-based species that possess attractive properties as materials, reagents and/ or catalysts. Results and DiscussionOur initial approachq uestioned whether the transmetallation reaction between [Au(IPr)Cl] (1)a nd an equimolar amount of phenylboronic acid was feasible in technical grade acetonei n the presence of K 2 CO 3 (entry 1, Ta ble 1). This initial hypothesis is based on our recent work using aw eak inorganic base to [a] N.

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Section: Introductionmentioning

confidence: 99%

Simple Synthetic Routes to N‐Heterocyclic Carbene Gold(I)–Aryl Complexes: Expanded Scope and Reactivity

Tzouras

Saab

Janssens

et al. 2020

Chemistry A European J

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“…Interestingly, the same research group found out that water is fundamental for such a reaction, except for studies with phenols and aryl alkynes. 11,56 Further, Nolan and Reek have recently confirmed the need for dual gold catalysis by encapsulation of the hydroxylated gold dimer. 54 Scheme 1.…”

Section: Introductionmentioning

confidence: 98%

“…The barrier for this transition state is 7.2 kcal/mol higher in energy with respect to the barrier that leads to the trans-product; the corresponding structures of IV differ in energy by 2.7 kcal/mol, with the structure on the trans-pathway being lower in energy, as previously reported yet. 56 Next, the reaction pathway for the simplified catalyst [Au(IMe)] + -where the 2,6-di(isopropyl)phenyl substituents on the NHC are substituted by methyl groups -was calculated ( Figure 2). Furthermore, first in Figure 2a the diphenylacetylene was replaced with but-2-yne for the sake of simplicity.…”

Section: Digold Catalysismentioning

confidence: 99%

“…55,56 However, in 2016 Zuccaccia and co-workers described the mechanism for the hydroxylation of alkynes, 37 accurately predicting the enthalpy barriers due to past benchmarking studies of the hydroamination of alkynes by Belpassi, Belanzoni and coworkers. 57 It is possible for hydroalkoxylation to follow a mono-or dualgold based mechanism.…”

Section: Introductionmentioning

confidence: 99%

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

et al. 2017

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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

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“…We continue to be interested in the development of highly efficient and environmentally benign catalytic methodologies for the synthesis of organic molecules; therefore, we sought to combine the advantages offered by an eco-friendly solvent-free protocol, and the atom-and step-economy of sequential strategies. We envisioned that if we could adapt our hydrophenoxylation protocol to solvent-free conditions, [7] to then apply cross-coupling strategies on the resulting product, in a sequential manner, this would permit access to more complex organic entities in an easily conducted diversity-oriented manner.…”

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confidence: 99%

[Au]/[Pd] Multicatalytic Processes: Direct One‐Pot Access to Benzo[c]chromenes and Benzo[b]furans

Oonishi

Gómez‐Suárez

Martín

et al. 2014

Chemistry A European J

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A new synthetic protocol that combines the advantages offered by eco-friendly solvent-free reactions and sequential transformations is reported. This strategy offers straightforward access to benzo[c]chromenes and benzo[b]furans from commercially available starting materials. This two-step, one-pot strategy consists of an Au-catalyzed hydrophenoxylation process followed by Pd-catalyzed C-H activation or Mizoroki-Heck reactions. The selectivity of the process towards C-H activation or Mizoroki-Heck reaction can be easily tuned.

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Acid, silver, and solvent-free gold-catalyzed hydrophenoxylation of internal alkynes

Cited by 12 publications

References 26 publications

Simple Synthetic Routes to N‐Heterocyclic Carbene Gold(I)–Aryl Complexes: Expanded Scope and Reactivity

Simple Synthetic Routes to N‐Heterocyclic Carbene Gold(I)–Aryl Complexes: Expanded Scope and Reactivity

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

[Au]/[Pd] Multicatalytic Processes: Direct One‐Pot Access to Benzo[c]chromenes and Benzo[b]furans

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