Toward a mechanistic understanding of oxidative homocoupling: the Glaser–Hay reaction

Jover, Jesús; Spuhler, Philipp S.; Zhao, Linlin; McArdle, Ciarán B.; Maseras, Feliu

doi:10.1039/c4cy00322e

Cited by 63 publications

(55 citation statements)

References 88 publications

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“…For copper-based MOFs ( Table 2, entry 4), the design of nascent MOFs is fairly derivativea nd is based on the proven efficiency of copperc omplexes such as Cu-TMEDA [205,206] or salts such as copper(II) acetate. For copper-based MOFs ( Table 2, entry 4), the design of nascent MOFs is fairly derivativea nd is based on the proven efficiency of copperc omplexes such as Cu-TMEDA [205,206] or salts such as copper(II) acetate.…”

Section: Mechanistic Descriptions Of Mof-mediated Coupling Reactionsmentioning

confidence: 99%

Engineering Metal–Organic Framework Catalysts for C−C and C−X Coupling Reactions: Advances in Reticular Approaches from 2014–2018

Kousik

Velmathi

2019

Chemistry A European J

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Metal-organic frameworks (MOFs) are ac lass of crystalline porousm aterials that have been activelyu sed for several industrial and synthetica pplications.M OFs are spatially and geometrically extrapolatedc oordination polymers with intriguing properties such as tunable porosity and dimensionality.Int erms of their catalytic efficiency,MOFs combine the easy recoverability of heterogeneous catalysts with the increased selectivity of biological catalysts. It is therefore not surprising that alot of work on optimizing MOF catalysts for organic transformationsh as been carriedo ut over the past decade. In this review,recent developments in MOF catalysis are summarized, with special attention being paid to CÀC, CÀN, and CÀOc oupling reactions. The influence of pore size, pore environment, and load on catalytic activity is described. Post-synthetics tabilization techniques and hostguest interactions in caged MOF scaffolds are detailed. Mechanistic aspects pertaining to the use of MOFs in asymmetric heterogeneousc atalysis are highlighted and categorized.

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Section: Mechanistic Descriptions Of Mof-mediated Coupling Reactionsmentioning

confidence: 99%

Engineering Metal–Organic Framework Catalysts for C−C and C−X Coupling Reactions: Advances in Reticular Approaches from 2014–2018

Kousik

Velmathi

2019

Chemistry A European J

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“…4 Despite extensive investigation, uncertainties remain concerning the mechanism of the homogeneous reaction, in particular in regard to the role of the role of gaseous oxygen. Recent theoretical studies indicate that both in the presence and in the absence of oxygen, the rate limiting step is de-protonation of the Cu-coordinated alkyne, 5 although direct experimental evidence is lacking. Reference 6 provides a comprehensive review of the history and applications of homogeneously catalyzed…”

Section: Introductionmentioning

confidence: 99%

Critical Role of Oxygen in Silver-Catalyzed Glaser–Hay Coupling on Ag(100) under Vacuum and in Solution on Ag Particles

et al. 2017

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The essential role of oxygen in enabling heterogeneously catalyzed Glaser−Hay coupling of phenylacetylene on Ag(100) was elucidated by STM, laboratory and synchrotron photoemission, and DFT calculations. In the absence of coadsorbed oxygen, phenylacetylene formed well-ordered dense overlayers which, with increasing temperature, desorbed without reaction. In striking contrast, even at 120 K, the presence of oxygen led to immediate and complete disruption of the organic layer due to abstraction of acetylenic hydrogen with formation of a disordered mixed layer containing immobile adsorbed phenylacetylide. At higher temperatures phenylacetylide underwent Glaser−Hay coupling to form highly ordered domains of diphenyldiacetylene that eventually desorbed without decomposition, leaving the bare metal surface. DFT calculations showed that, while acetylenic H abstraction was otherwise an endothermic process, oxygen adatoms triggered a reaction-initiating exothermic pathway leading to OH(a) + phenylacetylide, consistent with the experimental observations. Moreover, it was found that, with a solution of phenylacetylene in nonane and in the presence of O 2 , Ag particles catalyzed Glaser−Hay coupling with high selectivity. Rigorous exclusion of oxygen from the reactor strongly suppressed the catalytic reaction. Interestingly, too much oxygen lowers the selectivity toward diphenyldiacetylene. Thus, vacuum studies and theoretical calculations revealed the key role of oxygen in the reaction mechanism, subsequently borne out by catalytic studies with Ag particles that confirmed the presence of oxygen as a necessary and sufficient condition for the coupling reaction to occur. The direct relevance of model studies to a mechanistic understanding of coupling reactions under conditions of practical catalysis was reaffirmed.

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“…Ötvös et al explained the enhanced activity obtained using the Cu(II)Fe(III)‐LDH catalyst by the cooperative interactions between of Cu(II) and Cu(I) ions, which mediated the oxidative homocouplings of acetylenes and arylamines . The authors speculated that the Cu embedded in the LDH structure had the ability to change oxidation states during reaction, allowing a Cu(I)–Cu(II) cooperative mechanism (see Figure ).…”

Section: Cooperativity In Catalysts Based On An Ordered‐rigid Backbonementioning

confidence: 99%

Progress in the Design of Cooperative Heterogeneous Catalytic Materials for C–C Bond Formation

Khoury

Gadipelly

Pappuru

et al. 2019

Adv Funct Materials

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The application of cooperative heterogeneous catalysts for the promotion of C-C bond formation is of great potential for making such chemical processes more sustainable. In the design of such materials, the main challenges are to form specific catalytic sites and to control the cooperative interactions. Because of the high complexity inherent to cooperative active site interactions, much of the research is focused on so called "enzyme inspired-materials." The current Progress Report identifies three material subgroups that are characterized by a rigid-ordered backbone (layered material), a flexible backbone (polymer based), or a constrained-flexibleordered backbone (metal organic frameworks). In each of these material types, examples that illustrate how key structural and chemical characteristics functions are associated with the efficient promotion of the cooperative mechanism are highlighted. The limitations and strengths of each of the systems are considered with the aim of providing an outlook with regard to the minimum requirements needed to construct an efficient cooperative catalytic material. Given the current accumulated common knowledge in this area, it is suggested that getting inspiration from the synthetic existing systems is perhaps more beneficial than from enzymes.

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Toward a mechanistic understanding of oxidative homocoupling: the Glaser–Hay reaction

Cited by 63 publications

References 88 publications

Engineering Metal–Organic Framework Catalysts for C−C and C−X Coupling Reactions: Advances in Reticular Approaches from 2014–2018

Engineering Metal–Organic Framework Catalysts for C−C and C−X Coupling Reactions: Advances in Reticular Approaches from 2014–2018

Critical Role of Oxygen in Silver-Catalyzed Glaser–Hay Coupling on Ag(100) under Vacuum and in Solution on Ag Particles

Progress in the Design of Cooperative Heterogeneous Catalytic Materials for C–C Bond Formation

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