Theoretical study on the isomerization of propargyl derivative to conjugated diene under Au(I)-catalyzed reaction: A DFT study

Basak, Atanu; Chakrabarty, Kuheli; Ghosh, Animesh; Das, Gourab Kanti

doi:10.1016/j.comptc.2016.03.006

Cited by 7 publications

(6 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We termed it as soft propargylic deprotonation. A DFT study 61 supported the proposed mechanism of isomerization of alkyne to allene and further revealed that the propargylic deprotonation followed a syn-periplanar process. This isomerization strategy was later applied to ynamides and allenylamides (Scheme 7c) successfully to afford dienylamide products.…”

Section: Isomerization Of Alkyne/allene Into Dienementioning

confidence: 68%

Designed Bifunctional Ligands in Cooperative Homogeneous Gold Catalysis

Cheng

Zhang

2021

CCS Chem

View full text Add to dashboard Cite

Over the past two decades, homogeneous gold catalysis has experienced exponential development and contributed a plethora of highly valuable synthetic methods to the synthetic toolbox. Metalligand cooperative catalysis is a versatile strategy for achieving highly efficient and/or novel catalysis but has seldom been explored in gold chemistry. This minireview summarizes the progress we have made in developing remotely functionalized biaryl-2ylphosphine ligands and employing them in cooperative gold catalysis that achieves excellent catalytic efficiency or realizes previously unknown reactivities. This approach also provides new venues for implementing asymmetric gold catalysis.

show abstract

Section: Isomerization Of Alkyne/allene Into Dienementioning

confidence: 68%

Designed Bifunctional Ligands in Cooperative Homogeneous Gold Catalysis

Cheng

Zhang

2021

CCS Chem

View full text Add to dashboard Cite

show abstract

“…This difference in activation energy can be largely attributed to the indicated steric congestion in the latter and consistent with the observed high enantioselectivities. The deprotonation follows a syn-periplanar process 25 with the dihedral angle of Au-C1-C3-H being 11.2° in TS-allene-1 and 26.7° in TS-allene-2 . Subsequent cyclizations of the kinetically favored allenylgold E only need to overcome barriers of 3.8 kcal/mol and 2.1 kcal/mol to form the gold-coordinated cyclopentanols cis -4a-Au and trans -4a-Au , respectively.…”

Section: Resultsmentioning

confidence: 99%

Gold-catalysed asymmetric net addition of unactivated propargylic C–H bonds to tethered aldehydes

Cheng

Qian

et al. 2021

Nat Catal

View full text Add to dashboard Cite

The asymmetric one-step net addition of unactivated propargylic C-H bond to aldehyde leads to an atom-economic construction of versatile chiral propargylic alcohols but has not been realized previously. Here we show its implementation in an intramolecular manner under mild reaction conditions. Via cooperative gold catalysis enabled by a chiral bifunctional phosphine ligand, this chemistry achieves asymmetric catalytic deprotonation of propargylic C-H (pK a > 30) by a tertiary amine group (pK a ~ 10) of the ligand in the presence of much more acidic aldehydic α-hydrogens (pKa ~ 17). The reaction exhibits a broad scope and readily accommodates various functional groups. The 5-/6-membered ring fused homopropargylic alcohol products are formed with excellent enantiomeric excesses and high trans- selectivities with or without a preexisting substrate chiral center. DFT studies of the reaction support the conceived reaction mechanism and the calculated energetics corroborate the observed stereoselectivity and confirm an additional metal-ligand cooperation.

show abstract

“…Paton and Maseras computationally investigated σ-coordinated Au(I) allenyl cation structures, where these structures were recognized as intermediates in the hydroalkoxylation of allenes reaction . This triggered a number of experimental and computational reports of the functionalization of allenes with a variety of nucleophiles and metals, particularly hydration, , hydroamination, , and hydroalkoxylation, , where gold has been extensively investigated. − Although these studies were mostly focused on kinetics, ligand efficiency, and reversibility aspects of the reactions, a complete account of the reaction mechanism of the hydroalkoxylation of allene is yet to be presented.…”

Section: Introductionmentioning

confidence: 99%

Theoretical Insights into [NHC]Au(I) Catalyzed Hydroalkoxylation of Allenes: A Unified Reaction Valley Approach Study

2021

View full text Add to dashboard Cite

Hydroxylation is an effective approach for the synthesis of carbon–oxygen bonds and allylic ethers. The [NHC]Au(I) catalyzed intermolecular hydroalkoxylation of allene was studied at the DFT and Coupled Cluster level of theory. Using the Unified Reaction Valley Approach (URVA), we carry out a comprehensive mechanistic analysis of [NHC]Au(I)-catalyzed and noncatalyzed reactions. The URVA study of several possible reaction pathways reveal that the [NHC]Au(I) catalyst enables the hydroalkoxylation reaction to occur via a two step mechanism based upon the Au ability to switch between π- and σ-complexation. The first step of the mechanism involves the formation of a CO bond after the transition state with no energy penalty. Following the CO bond breakage, the OH bond breaks and CH bond forms during the second step of the mechanism, as the catalyst transforms into the more stable π–Au complex. The URVA results were complemented with local vibrational mode analysis to provide measures of intrinsic bond strength for Au(I)-allene interactions of all stationary points, and NBO analysis was applied in order to observe charge transfer events along the reaction pathway. Overall, the π–Au CC interactions of the products are stronger than those of the reactants adding to their exothermicity. Our work on the hydroxylation of allene provides new insights for the design of effective reaction pathways to produce allylic ethers and also unravels new strategies to form C–O bonds by activation of CC bonds.

show abstract

Theoretical study on the isomerization of propargyl derivative to conjugated diene under Au(I)-catalyzed reaction: A DFT study

Cited by 7 publications

References 42 publications

Designed Bifunctional Ligands in Cooperative Homogeneous Gold Catalysis

Designed Bifunctional Ligands in Cooperative Homogeneous Gold Catalysis

Gold-catalysed asymmetric net addition of unactivated propargylic C–H bonds to tethered aldehydes

Theoretical Insights into [NHC]Au(I) Catalyzed Hydroalkoxylation of Allenes: A Unified Reaction Valley Approach Study

Contact Info

Product

Resources

About