Quantitative Catalyst−Substrate Association Relationships between Metathesis Molybdenum or Ruthenium Carbene Complexes and Their Substrates

Kim, Kyung Hwan; Ok, Taedong; Lee, Kwangyeol; Lee, Jun Young; Chang, Kyu Tae; Ihee, Hyotcherl; Sohn, Jae Hak

doi:10.1021/ja104193s

Cited by 28 publications

(19 citation statements)

References 47 publications

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“…86 In a subsequent study, molybdenum complexes were shown to favour alkyne over alkene over allene, while first generation ruthenium complexes favoured allene over alkene over alkyne. 87 Second-generation ruthenium complexes favoured alkyne over allene over alkene. Understanding this order of selectivity is important in the design of cascade metathesis reactions.…”

Section: First-versus Second-generation Pre-catalystsmentioning

confidence: 99%

Key processes in ruthenium-catalysed olefin metathesis

et al. 2014

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While the fundamental series of [2+2]cycloadditions and retro[2+2]cycloadditions that make up the pathways of ruthenium-catalysed metathesis reactions is well-established, the exploration of mechanistic aspects of alkene metathesis continues. In this Feature Article, modern mechanistic studies of the alkene metathesis reaction, catalysed by well-defined ruthenium complexes, are discussed. Broadly, these concern the processes of pre-catalyst initiation, propagation and decomposition, which all have a considerable impact on the overall efficiency of metathesis reactions.

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Section: First-versus Second-generation Pre-catalystsmentioning

confidence: 99%

Key processes in ruthenium-catalysed olefin metathesis

et al. 2014

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“…[6,[17][18][19]21] This catalytic process is even more complex, since two different pathways can be distinguished for the yne-then-ene mechanism depending on the substrate orientation, that is, the exo (Scheme 2 b) and the endo (Scheme 2 c) approaches, which in general lead to different products. [6,9,17,18] However, even if formation of the endo product seems plausible, it is usually not observed when an Ru-based catalyst is used, or it is only observed in minor amounts.…”

Section: Introductionmentioning

confidence: 99%

Mechanistic Insights into Ring‐Closing Enyne Metathesis with the Second‐Generation Grubbs–Hoveyda Catalyst: A DFT Study

Núñez‐Zarur

Solans‐Monfort

Rodrı́guez-Santiago

et al. 2011

Chemistry A European J

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The full catalytic process (precatalyst activation, propagating cycle and active-species interconversion) of the ring-closing enyne metathesis (RCEYM) reaction of 1-allyloxy-2-propyne with the Grubbs-Hoveyda complex as catalyst was studied by B3LYP density functional theory. Both the ene-then-yne and yne-then-ene pathways are considered and, for the productive catalytic cycle, the feasibility of the endo-yne-then-ene route is also explored. Calculations predict that the ene-then-yne and yne-then-ene pathways proceed through equivalent steps, the only major difference being the order in which they take place. In this way, all alkene metathesis processes studied here involve four steps: olefin coordination, cycloaddition, cycloreversion and olefin decoordination. Among them, the two more energetically demanding ones are the olefin coordination and decoordination steps. The reaction of the alkyne fragment consists of two steps: alkyne coordination and alkyne skeletal reorganization, the latter of which has the highest Gibbs energy barrier. Comparison between the ene-then-yne and yne-then-ene pathways shows that there is no clear energetic preference for either of the two processes, and thus both should be operative when unsubstituted enynes are involved. In addition, although the endo orientation is computed to be slightly disfavored, it is not ruled out for 1-allyloxy-2-propyne, and thus calculations seem to indicate that the exo versus endo selectivity is strongly influenced by the presence of substituents in the reagent.

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“…Rates of reaction of dye-functionalized alkenes, alkynes and allenes with various metathesis (pre-)catalysts 67,68. …”

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confidence: 99%

The Influence of Structure on Reactivity in Alkene Metathesis

Nelson

Percy

2014

Advances in Physical Organic Chemistry

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Alkene metathesis has grown from a niche technique to a common component of the synthetic organic chemistry toolbox, driven in part by the development of more active catalyst systems, or those optimized for particular purposes. While the range of synthetic chemistry achieved has been exciting, the effects of structure on reactivity have not always been particularly clear, and rarely quantified. Understanding these relationships is important when designing new catalysts, reactions, and syntheses. Here, we examine what is known about the effect of structure on reactivity from two perspectives: the catalyst, and the substrate. The initiation of the pre-catalyst determines the rate at which active catalyst enters the catalytic cycle; the rate and selectivity of the alkene metathesis reaction is dependent on how the substrate and active catalyst interact. The tools deployed in modern studies of mechanism and structure/activity relationships in alkene metathesis are discussed.

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Quantitative Catalyst−Substrate Association Relationships between Metathesis Molybdenum or Ruthenium Carbene Complexes and Their Substrates

Cited by 28 publications

References 47 publications

Key processes in ruthenium-catalysed olefin metathesis

Key processes in ruthenium-catalysed olefin metathesis

Mechanistic Insights into Ring‐Closing Enyne Metathesis with the Second‐Generation Grubbs–Hoveyda Catalyst: A DFT Study

The Influence of Structure on Reactivity in Alkene Metathesis

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