Sequential mechanism in the oxidative demetalation of a trimethylenemethane-iron tricarbonyl complex, tricarbonyl[((1-3,6-.eta.)-2-methylenecyclopentane-1,3-diyl]iron

Mondo, James A.; Berson, Jerome A.

doi:10.1021/ja00348a066

Cited by 20 publications

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“…Although it mainly concerns transition metal (Pd, Ni) catalyzed reactions, it departs from and refers to the stabilization and reactivity of TMM coordinated to tricarbonyliron. [242][243][244] The Pd-catalyzed [3+2] cycloaddition reactions of TMM precursors to electron-deficient alkenes have been suggested to proceed via zwitterionic (η 3 -TMM)PdL 2 complexes. [245][246][247][248][249][250] Ten years later, the groups of Wojcicki 251,252 and Chen 253 were the first to isolate and structurally characterize such species.…”

Section: Activation Of the 13-dipolementioning

confidence: 99%

“…Two reviews, by Trost, and by Binger and Büch, are on the synthesis of five-membered rings by [3+2] cycloaddition of (1,3-dipolar) trimethylenemethane (TMM) and synthetic equivalents (see also ref ). Although it mainly concerns transition metal (Pd, Ni) catalyzed reactions, it departs from and refers to the stabilization and reactivity of TMM coordinated to tricarbonyliron. − The Pd-catalyzed [3+2] cycloaddition reactions of TMM precursors to electron-deficient alkenes have been suggested to proceed via zwitterionic (η 3 -TMM)PdL 2 complexes. − Ten years later, the groups of Wojcicki , and Chen were the first to isolate and structurally characterize such species. Both, the analogous Pt(η 3 -TMM) ( 130 , eq 36) 251 and Pd(η 3 -TMM) ( 131 , eq 37) 253 complexes, at room temperature readily undergo stoichiometric [3+2] cycloaddition to, e.g., TCNE and maleic anhydride.…”

Section: Activation Of the 13-dipolementioning

confidence: 99%

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Metal-Assisted Cycloaddition Reactions in Organotransition Metal Chemistry

1997

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Section: Activation Of the 13-dipolementioning

confidence: 99%

Section: Activation Of the 13-dipolementioning

confidence: 99%

Metal-Assisted Cycloaddition Reactions in Organotransition Metal Chemistry

1997

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Iron: Organometallic ChemistryBased in part on the article Iron: Organometallic Chemistry by James R. Green which appeared in theEncyclopedia of Inorganic Chemistry, First Edition.

Paley¹

2005

Encyclopedia of Inorganic Chemistry

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Studies involving the preparation, reactivity, and properties of the organometallic complexes of iron (compounds possessing a FeC bond) have played a central role in the growth of organometallics as a major subdiscipline with chemistry. From the discovery of ferrocene in the 1950s to the present day, interest and research activity remain high. This entry provides a survey of this large and diverse area of organometallic chemistry, and is arranged by increasing hapticity of the organic ligand of interest that is bound to iron. Included are discussions of the chemistry of iron σ‐alkyl, acyl, alkynyl, and vinyl complexes, iron carbenes, η1‐ and η3‐allyl iron complexes, η2‐alkene and η4‐diene iron complexes, trimethylenemethane and cyclobutadiene complexes of iron, cationic iron pentadienyl, cyclohexadienyl, and arene complexes, and ferrocenes and heteroferrocenes.

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[3+2] Cycloaddition of Trimethylenemethane and its Synthetic Equivalents

Yamago

Nakamura

2002

Organic Reactions

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Trimethylenemethane (TMM) is a non‐Kekulé molecule composed of four carbons, six hydrogens, and four π‐orbitals. Therefore, TMM can only be expressed as resonance structures involving 1,3‐diyls and zwitterions. The two degenerate nonbonding molecular orbitals in the Hückel molecular orbital of TTM indicate the existence of singlet and triplet electronic configurations, which play significant roles in the TMM chemistry. TMMs were imaginary molecules until the late 1960's, and parent TMM was first isolated in a low‐temperature matrix. It is stable for several weeks at 77 K, and is a ground‐state triplet with a D 3 h ‐planar structure as assigned by ESR spectroscopy. The unique structures coupled with the complex electronic states of TMM derivatives have been topics of theoretical, mechanistic, and synthetic studies. By analogy with the Diels‐Alder reaction for the synthesis of six‐membered rings through [4 + 2] cycloadditions, the use of TMM as a three‐carbon unit for [3 + 2] cycloadditions appears to represent a viable synthetic possibility, because the four π‐electron orbital system of TMM is theoretically suitable for the [4π s + 2π s ] cycloaddition. As expected, however, rapid ring closure to methylenecyclopropane (MCP) is preferred to cycloaddition with a 2π acceptor. Therefore, for synthetic use, tailor‐made derivatives of TMM and its equivalents need to be designed to achieve [3 + 2] cycloaddition reactions. The first breakthrough in the use of TMMs for [3 + 2] cycloaddition reactions was reported in the reaction of isopropylidenecyclopentane‐1,3‐diyl, which has a considerable lifetime and reacts with electron‐deficient alkenes. Because the parent TMM gives methylenecyclopropane and many MCP derivatives undergo thermal isomerization, MCPs have been considered to serve as precursors for TMMs. However, direct evidence for the formation of TMMs from MCPs and their synthetic use as TMM precursors was rather scant until recently. Since TMM species are generally too short‐lived and too reactive to be used for organic synthesis, various attempts have been made to stabilize them with transition metal templates. Efficient transition metal catalyzed TMM cycloaddition is achieved using MCPs and Ni(0) or Pd(0) catalysts. The reaction proceeds via ring opening of the MCP to form (methylene)metallacyclobutane‐type intermediates. More recently, Pd(0)‐catalyzed reactions of [2‐(acetoxymethyl)allyl]trimethyl‐silane with 2π acceptors have emerged as a powerful method for cyclopentane synthesis. This reaction is considered to involve the zwitterionic TMM‐Pd intermediate. The reaction serves well for the [3 + 2] cycloaddition to electron‐deficient acceptors, and it has been applied to the synthesis of several cyclopentanoid natural products. This review surveys the [3 + 2] cycloaddition reactions of TMMs and their metal complexes to 2π acceptors. The reactions are divided into five categories, defined by reaction types and precursors: (1) cycloadditions of free TMMs generated from diazenes, (2) cycloadditions of free TMMs generated from MCPs, (3) transition metal catalyzed reactions of MCPs, (4) transition metal catalyzed reactions of silylated allylic acetates, and (5) cycloaddition of stable TMM‐metal complexes. Transformations that accomplish a net cycloaddition but require several steps using TMM equivalents are not covered. Various aspects of TMMs, including physical and synthetic chemistry, have already been reviewed.

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Sequential mechanism in the oxidative demetalation of a trimethylenemethane-iron tricarbonyl complex, tricarbonyl[((1-3,6-.eta.)-2-methylenecyclopentane-1,3-diyl]iron

Cited by 20 publications

References 0 publications

Metal-Assisted Cycloaddition Reactions in Organotransition Metal Chemistry

Metal-Assisted Cycloaddition Reactions in Organotransition Metal Chemistry

Iron: Organometallic ChemistryBased in part on the article Iron: Organometallic Chemistry by James R. Green which appeared in theEncyclopedia of Inorganic Chemistry, First Edition.

[3+2] Cycloaddition of Trimethylenemethane and its Synthetic Equivalents

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