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  2. Buchner ring expansion - Wikipedia

    en.wikipedia.org/wiki/Buchner_ring_expansion

    The Buchner ring expansion is a two-step organic C-C bond forming reaction used to access 7-membered rings. The first step involves formation of a carbene from ethyl diazoacetate , which cyclopropanates an aromatic ring.

  3. Ring expansion and contraction - Wikipedia

    en.wikipedia.org/wiki/Ring_expansion_and_contraction

    The strategy can start with a Simmons-Smith-like cyclopropanation of a cyclic alkene. [8] A related cyclopropane-based ring expansion is the Buchner ring expansion. The Buchner ring expansion is used to convert arenes to cycloheptatrienes. The Buchner ring expansion is encouraged to open to the desired product by placing electron withdrawing ...

  4. Carbene - Wikipedia

    en.wikipedia.org/wiki/Carbene

    Carbenes had first been postulated by Eduard Buchner in 1903 in cyclopropanation studies of ethyl diazoacetate with toluene. [29] In 1912 Hermann Staudinger [30] also converted alkenes to cyclopropanes with diazomethane and CH 2 as an intermediate. Doering in 1954 demonstrated their synthetic utility with dichlorocarbene. [31]

  5. Intramolecular reactions of diazocarbonyl compounds - Wikipedia

    en.wikipedia.org/wiki/Intramolecular_reactions...

    The reaction mechanism of decomposition of diazocarbonyl compounds with copper begins with the formation of a copper carbene complex. Evidence for the formation of copper carbenes is provided by comparison to the behavior of photolytically generated free carbenes [6] and the observation of appreciable enantioselectivity in cyclopropanations with chiral copper complexes. [7]

  6. Cyclopropanation - Wikipedia

    en.wikipedia.org/wiki/Cyclopropanation

    Cyclopropanation is also stereospecific as the addition of carbene and carbenoids to alkenes is a form of a cheletropic reaction, with the addition taking place in a syn manner. For example, dibromocarbene and cis -2-butene yield cis -2,3-dimethyl-1,1-dibromocyclopropane, whereas the trans isomer exclusively yields the trans cyclopropane.

  7. Jay-Z, Diddy accusations create mystery surrounding female ...

    www.aol.com/jay-z-diddy-accusations-create...

    Questions surrounding the identity of "Celebrity B" remain after Jay-Z was recently named in a Sean "Diddy" Combs sexual assault lawsuit.. Initially, the lawsuit stated Diddy raped the minor while ...

  8. This Family Drives 350 Miles For What Could Be A Common ...

    projects.huffingtonpost.com/dying-to-be-free...

    Noting that medication-assisted treatment “is a high priority” for HHS, a department spokesperson told HuffPost in late December that the agency is “working quickly to update the rules.” Making sure that every opioid addict who wants medication-assisted treatment can receive it — the Obama administration’s goal — will require a ...

  9. Metal-catalyzed cyclopropanations - Wikipedia

    en.wikipedia.org/wiki/Metal-catalyzed_cyclopropa...

    Cyclopropanation of olefins with diazocarbonyl compounds is commonly accomplished using rhodium carboxylate complexes, although copper was originally used. [11] The scope of the olefin is generally quite broad—electron-rich, [ 12 ] neutral, [ 13 ] and electron-poor [ 14 ] olefins have all been cyclopropanated efficiently using rhodium-based ...