Catalytic Dinuclear Nickel Spin Crossover Mechanism and Selectivity for Alkyne Cyclotrimerization

Computational chemistry provides a versatile toolbox for studying mechanistic details of catalytic reactions and holds promise to deliver practical strategies to enable the rational in silico catalyst design. The versatile reactivity and nontrivial electronic structure effects, common for systems based on 3d transition metals, introduce additional complexity that may represent a particular challenge to the standard computational strategies. In this review, we discuss the challenges and capabilities of modern electronic structure methods for studying the reaction mechanisms promoted by 3d transition metal molecular catalysts. Particular focus will be placed on the ways of addressing the multiconfigurational problem in electronic structure calculations and the role of expert bias in the practical utilization of the available methods. The development of density functionals designed to address transition metals is also discussed. Special emphasis is placed on the methods that account for solvation effects and the multicomponent nature of practical catalytic systems. This is followed by an overview of recent computational studies addressing the mechanistic complexity of catalytic processes by molecular catalysts based on 3d metals. Cases that involve noninnocent ligands, multicomponent reaction systems, metal–ligand and metal–metal cooperativity, as well as modeling complex catalytic systems such as metal–organic frameworks are presented. Conventionally, computational studies on catalytic mechanisms are heavily dependent on the chemical intuition and expert input of the researcher. Recent developments in advanced automated methods for reaction path analysis hold promise for eliminating such human-bias from computational catalysis studies. A brief overview of these approaches is presented in the final section of the review. The paper is closed with general concluding remarks.

show abstract

Section: Mechanistic Complexity In Catalysis By 3d Transition Metalsmentioning

confidence: 99%

Computational Approach to Molecular Catalysis by 3d Transition Metals: Challenges and Opportunities

et al. 2018

View full text Add to dashboard Cite

show abstract

“…Moreover, using analogous Ni(0) benzene complex, several catalytic reactions, such as the hydrosilylation and cyclotrimerization of alkynes, were performed on the dinickel centers without breakage of the dinuclear framework. Detailed theoretical studies were conducted by Uyeda and Ess et al to reveal the mechanism of catalytic alkyne cyclotrimerization ( Scheme 17 ) [ 81 ]. Interestingly, oxidative C–C bond coupling of terminal alkynes occurs on the dinickel centers, and migratory insertion of the third alkyne provides chemoselective formation of benzene derivatives, while the reaction occurs via another pathway in the mononuclear catalyst system to provide different product selectivity.…”

Section: Catalytic Applicationsmentioning

confidence: 99%

Dinuclear Nickel(I) and Palladium(I) Complexes for Highly Active Transformations of Organic Compounds

2018

View full text Add to dashboard Cite

In typical catalytic organic transformations, transition metals in catalytically active complexes are present in their most stable valence states, such as palladium(0) and (II). However, some dimeric monovalent metal complexes can be stabilized by auxiliary ligands to form diamagnetic compounds with metal–metal bonding interactions. These diamagnetic compounds can act as catalysts while retaining their dimeric forms, split homolytically or heterolytically into monomeric forms, which usually have high activity, or in contrast, become completely deactivated as catalysts. Recently, many studies using group 10 metal complexes containing nickel and palladium have demonstrated that under specific conditions, the active forms of these catalyst precursors are not mononuclear zerovalent complexes, but instead dinuclear monovalent metal complexes. In this mini-review, we have surveyed the preparation, reactivity, and the catalytic processes of dinuclear nickel(I) and palladium(I) complexes, focusing on mechanistic insights into the precatalyst activation systems and the structure and behavior of nickel and palladium intermediates.

show abstract

“…To complete the coordination sphere of the nickels, a benzene was introduced as a π-bridging ligand (Figure I.4a). 36 This specific complexes can promote a large variety of cyclisations [37][38][39][40][41][42][43] like alkyne cyclotrimerisation, [4+1] cycloaddition of diene, cyclopropanation and the Pauson-Khand reaction. The groups of Bera 44 and Tilley, 45 45 In naphthyridine complexes, the C-H reaction can occur on the naphthyridine ligand itself or on another reactant coordinated to the metal(s).…”

Section: -Introduction 1 -Naphthyridine Based Complexesmentioning

confidence: 99%

Unsymmetrical Naphthyridine-Based Dicopper(I) Complexes: Synthesis, Stability, and Carbon–Hydrogen Bond Activations

et al. 2021

View full text Add to dashboard Cite

Two unsymmetrical dinucleating naphthyridine-based ligands with di(pyridyl) and phosphino side arms were employed in the synthesis of dicopper(I) chloride cores that activate NaBPh 4 to afford bridging phenyl organocopper complexes. In these compounds, the bridging ligand binds symmetrically, as observed in previously described symmetrical dicopper(I) complexes supported by naphthyridine-based ligands with two di(pyridyl) side arms. Unlike the symmetrical systems, however, these complexes undergo quasireversible electrochemical reductions, and chemical reduction yields a diamagnetic product resulting from the coupling of naphthyridine-based radicals of two complexes. The μ-Ph complexes activate the C−H bonds of terminal alkynes and the electron-poor arene C 6 F 5 H. By DFT calculations, the mechanism of terminal alkyne activation involves H-atom transfer at the cationic dicopper center and is sensitive to subtle changes in copper-ligand interactions as well as the position of the anion.

show abstract

Catalytic Dinuclear Nickel Spin Crossover Mechanism and Selectivity for Alkyne Cyclotrimerization

Cited by 39 publications

References 115 publications

Computational Approach to Molecular Catalysis by 3d Transition Metals: Challenges and Opportunities

Computational Approach to Molecular Catalysis by 3d Transition Metals: Challenges and Opportunities

Dinuclear Nickel(I) and Palladium(I) Complexes for Highly Active Transformations of Organic Compounds

Unsymmetrical Naphthyridine-Based Dicopper(I) Complexes: Synthesis, Stability, and Carbon–Hydrogen Bond Activations

Contact Info

Product

Resources

About