Base-Metal-Catalyzed Olefin Isomerization Reactions

Liu, Xufang; Li, Bin; Liu, Qiang

doi:10.1055/s-0037-1612014

Cited by 78 publications

(46 citation statements)

References 56 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The KIE is temperature independent, and thus tunneling does not play a role in the reaction mechanism. The combined experimental results are most consistent with alkene isomerization by 2 occurring by the allyl mechanism, akin to many other low valent iron complexes …”

Section: Results and Discussionsupporting

confidence: 69%

Two-State Reactivity in Iron-Catalyzed Alkene Isomerization Confers σ-Base Resistance

et al. 2020

View full text Add to dashboard Cite

A low-coordinate, high spin (S = 3/2) organometallic iron(I) complex is a catalyst for the isomerization of alkenes. A combination of experimental and computational mechanistic studies supports a mechanism in which alkene isomerization occurs by the allyl mechanism. Importantly, while substrate binding occurs on the S = 3/2 surface, oxidative addition to an η1-allyl intermediate only occurs on the S = 1/2 surface. Since this spin state change is only possible when the alkene substrate is bound, the catalyst has high immunity to typical σ-base poisons due to the antibonding interactions of the high spin state.

show abstract

Section: Results and Discussionsupporting

confidence: 69%

Two-State Reactivity in Iron-Catalyzed Alkene Isomerization Confers σ-Base Resistance

et al. 2020

View full text Add to dashboard Cite

show abstract

“…Transition metal-catalyzed alkene isomerization has emerged as a fundamental and atom-economic transformation, which can readily convert terminal alkenes to internal alkenes . Prior reports of alkene isomerization usually rely on noble metals, such as ruthenium, rhodium, palladium, iridium, and platinum .…”

Section: Introductionmentioning

confidence: 99%

Cobalt(II)-Catalyzed Stereoselective Olefin Isomerization: Facile Access to Acyclic Trisubstituted Alkenes

et al. 2020

View full text Add to dashboard Cite

Stereoselective synthesis of trisubstituted alkenes is a long-standing challenge in organic chemistry, due to the small energy differences between E and Z isomers of trisubstituted alkenes (compared with 1,2-disubstituted alkenes). Transition metal-catalyzed isomerization of 1,1-disubstituted alkenes can serve as an alternative approach to trisubstituted alkenes, but it remains underdeveloped owing to issues relating to reaction efficiency and stereoselectivity. Here we show that a novel cobalt catalyst can overcome these challenges to provide an efficient and stereoselective access to a broad range of trisubstituted alkenes. This protocol is compatible with both mono- and dienes and exhibits a good functional group tolerance and scalability. Moreover, it has proven to be a useful tool to construct organic luminophores and a deuterated trisubstituted alkene. A preliminary study of the mechanism suggests that a cobalt-hydride pathway is involved in the reaction. The high stereoselectivity of the reaction is attributed to both a π–π stacking effect and the steric hindrance between substrate and catalyst.

show abstract

“…Owing to its high natural abundance, biocompatibility, and unique catalysis, earth-abundant transition metal catalysts such as iron, cobalt, nickel, and copper have attracted much attention in the past two decades. − , The earth-abundant transition metals have been considered as an alternative to noble metals for alkene isomerization. In combination with appropriate ligands, cobalt complexes have been demonstrated as efficient catalysts for position isomerization of alkenes. − In the 1970s, Orchin and co-workers found cobalt hydride complex [CoH(Co) 4 ] could catalyze isomerization of ally benzene and proposed a Co–H insertion/β-H elimination pathway based on deuterium-labeling experiments .…”

mentioning

confidence: 99%

Cobalt-CatalyzedZtoEIsomerization of Alkenes: An Approach to (E)-β-Substituted Styrenes

Cai

et al. 2020

Org. Lett.

View full text Add to dashboard Cite

An efficient cobalt-catalyzed Z to E isomerization of βsubstituted styrenes using the amido-diphosphine ligand was developed, delivering the (E)-isomers with good functional tolerance and high stereoselectivity. The reaction could be scaled up to gram-scale with a catalyst loading of 0.1 mol %, using a mixture of (Z)-and (E)-alkene as the starting material. Preliminary mechanistic studies indicated that cobalt(I)-hydride and a benzylic-cobalt species were probably involved in the reaction, as supported by experiments and DFT calculations.

show abstract

Base-Metal-Catalyzed Olefin Isomerization Reactions

Cited by 78 publications

References 56 publications

Two-State Reactivity in Iron-Catalyzed Alkene Isomerization Confers σ-Base Resistance

Two-State Reactivity in Iron-Catalyzed Alkene Isomerization Confers σ-Base Resistance

Cobalt(II)-Catalyzed Stereoselective Olefin Isomerization: Facile Access to Acyclic Trisubstituted Alkenes

Cobalt-CatalyzedZtoEIsomerization of Alkenes: An Approach to (E)-β-Substituted Styrenes

Contact Info

Product

Resources

About