Catalysis of H‐D Exchange in Cyclooctatetraene by Cycloocta‐1,3,5‐triene

Schröder, Gerhard

doi:10.1002/anie.196300453

Cited by 3 publications

(3 citation statements)

References 3 publications

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“…Each of these MO + was found to be substantially more effective at dehydrogenation to produce MO + L than were the corresponding naked M + at forming M + L; note that L is used generically and the 'L' in MO + L may differ from the L in M + L. Many condensed phase organorhenium oxide compounds have been identified [8] and the ReO + L produced here correspond to condensed phase X Re III O {y L} (X=halogen) compounds [33]. Early (groups III and IV) transition metal MO + exhibit very strong M + O bonds which do not oxidize organic substrates [34]. Furthermore, the zero (group III) or one (group IV) free valence electrons remaining at the metal center in these MO + are insufficient to allow efficient oxidative insertion/activation of C H or C C bonds and accordingly relatively inert behavior is generally exhibited for early transition metal MO + .…”

Section: Mo + and Tc 2 +mentioning

confidence: 94%

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Gas-phase reactions of Tc+, Re+, Mo+ and Cu+ with alkenes

Gibson

1998

Journal of Organometallic Chemistry

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Section: Mo + and Tc 2 +mentioning

confidence: 94%

“…Some later first-row transition metals exhibit sufficiently small BDE[MO + ] (B400 kJ mol − 1 ) that oxidation processes are important; e.g. FeO + oxidizes methane to methanol [34]. The BDE of MoO + is ca.…”

Section: Mo + and Tc 2 +mentioning

confidence: 99%

Gas-phase reactions of Tc+, Re+, Mo+ and Cu+ with alkenes

Gibson

1998

Journal of Organometallic Chemistry

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“…Gas-phase studies are particularly suited for the elucidation of mechanistic aspects, since they are not hampered by disturbing factors such as aggregation phenomena, solvent or 'gegenion' effects prevailing in the liquid phase. Recently, we have investigated C-H bond activation of benzene [6], toluene [7], ethane [8], and methane [9] by 'bare' FeO' in the gas phase'). An intriguing aspect of the C-H bond activation mediated by metal oxides concerns the face selectivity of the reaction, and bicyclo[2.2. llheptane (1 ; norbornane) is an ideal substrate due to the rigidity of the molecule.…”

Section: Ohmentioning

confidence: 99%

exo/endo‐Selectivity in the Reaction of ‘Bare’ FeO⁺ with Bicyclo[2.2.1]heptane (Norbornane)

Schwarz

1995

Helvetica Chimica Acta

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(4. IV. 95) 'Bare' FeO' reacts in the gas phase with norbornane with collision efficiency, and the most prominent cationic products correspond to [FeC,H,]+ (32%), [FeC,H,] Although the reactions are preceded and/or accompanied by partial H/D exchange, the isotope distribution in the product ions clearly points to a preferential endo-attack of bare FeO+, with an endolexo-ratio of ca. 10.3 and kinetic isotope effects kH/kD for the endo-abstraction of 2.4 and of 7.7 for approaching an exo-C-H bond. The preferred endo-approach of bicyclo[2.2.l]heptane by 'hare' FeO' is in distinct contrast to the P-450-mediated or the iron(ll1)porphyrin-catalyzed hydroxylation of this substrate which favor reactions at the exo-face.Selective 0-atom transfer from molecular oxygen to unactivated organic substrates such as saturated and/or unsaturated hydrocarbons is of fundamental importance in organic chemistry, biochemistry, and chemical industry [ 11. In biological systems, oxidative transformations are mediated by the iron-centered cytochrome P-450 [2] and related enzyme systems. P-450 is known to mediate hydroxylation of, for example, fatty acids, arenes, as well as the oxidative metabolization of xenobiotic compounds. These enzymes have received considerable interest, since there exist no adequate 'synthetic analogs' in preparative organic chemistry. In condensed-phase studies, addressing the question of the stereochemistry of the hydroxylation of norbornane (1) by reconstituted P-450 [3] as well as by highly halogenated Fe" '-porphyrins [4], the experimental findings point to the absence of carbocationic skeletal rearrangements, and the loss of stereochemistry together with large primary kinetic isotope effects (KIEs) provide strong evidence for a radical cage rebound mechanism (see Scheme I ) [2] [3] [5]. Abstraction of both exo-and endo-H-atoms from C(2) via a free-radical process was also observed, and the investigation of all-exo-(2,3,5,6-*H4)norbornane (4) demonstrated a substantial loss of stereospecificity. However, the P-450 and the Fell'-porphyrins have in common a large exo/ endo-preference [4].

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Tetradehydrodinaphtho[10]annulene and its transformation into zethrene: A hitherto unknown dehydroannulene and a forgotten aromatic hydrocarbon

Umeda

Hibi

Miki

et al. 2010

Pure and Applied Chemistry

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The synthesis and structural characterization of a hitherto unknown tetradehydrodinaphtho[10]annulene, which had eluded isolation since attempts initiated during the late 1960s, was achieved. Moreover, the dehydroannulene was transformed into stable derivatives of zethrene, which was first reported in 1955, but forgotten for a long time. These molecules are substituted at the 7,14-positions and open the door to the zethrene family for potential application as optoelectronic materials.

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Catalysis of H‐D Exchange in Cyclooctatetraene by Cycloocta‐1,3,5‐triene

Cited by 3 publications

References 3 publications

Gas-phase reactions of Tc+, Re+, Mo+ and Cu+ with alkenes

Gas-phase reactions of Tc+, Re+, Mo+ and Cu+ with alkenes

exo/endo‐Selectivity in the Reaction of ‘Bare’ FeO⁺ with Bicyclo[2.2.1]heptane (Norbornane)

Tetradehydrodinaphtho[10]annulene and its transformation into zethrene: A hitherto unknown dehydroannulene and a forgotten aromatic hydrocarbon

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Catalysis of H‐D Exchange in Cyclooctatetraene by Cycloocta‐1,3,5‐triene

Cited by 3 publications

References 3 publications

Gas-phase reactions of Tc+, Re+, Mo+ and Cu+ with alkenes

Gas-phase reactions of Tc+, Re+, Mo+ and Cu+ with alkenes

exo/endo‐Selectivity in the Reaction of ‘Bare’ FeO+ with Bicyclo[2.2.1]heptane (Norbornane)

Tetradehydrodinaphtho[10]annulene and its transformation into zethrene: A hitherto unknown dehydroannulene and a forgotten aromatic hydrocarbon

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exo/endo‐Selectivity in the Reaction of ‘Bare’ FeO⁺ with Bicyclo[2.2.1]heptane (Norbornane)