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  2. Ketene cycloaddition - Wikipedia

    en.wikipedia.org/wiki/Ketene_cycloaddition

    The progress of the reaction can be estimated by disappearance of the characteristic yellow color of the ketene, by loss of the band at about 2100 cm −1 in the infrared spectrum, or by 1 H NMR spectroscopy. Ketene, monoalkylketenes, and dimethylketene are usually allowed to react at or below room temperature, whereas the higher molecular ...

  3. ZACA reaction - Wikipedia

    en.wikipedia.org/wiki/ZACA_reaction

    The zirconium-catalyzed asymmetric carbo-alumination reaction (or ZACA reaction) was developed by Nobel laureate Ei-ichi Negishi. [1] It facilitates the chiral functionalization of alkenes using organoaluminium compounds under the influence of chiral bis-indenylzirconium catalysts (e.g. bearing chiral terpene residues, [2] as in (+)- or (−)-bis[(1-neomenthyl)indenyl]zirconium dichloride [3 ...

  4. Sharpless asymmetric dihydroxylation - Wikipedia

    en.wikipedia.org/wiki/Sharpless_asymmetric_di...

    The reaction has been applied to alkenes of virtually every substitution, often high enantioselectivities are realized, with the chiral outcome controlled by the choice of dihydroquinidine (DHQD) vs dihydroquinine (DHQ) as the ligand. Asymmetric dihydroxylation reactions are also highly site selective, providing products derived from reaction ...

  5. Diisopinocampheylborane - Wikipedia

    en.wikipedia.org/wiki/Diisopinocampheylborane

    Because of the large size of the α-pinenyl substituents, diisopinocampheylborane only hydroborates unhindered alkenes. These reactions proceed with high enantioselectivity. 2-Butene, 2-pentene, 3-hexene are converted to the respective chiral alcohols in high ee's. [4] Norbornene under the same conditions gave an 83% ee.

  6. Dihydroxylation - Wikipedia

    en.wikipedia.org/wiki/Dihydroxylation

    The Sharpless asymmetric dihydroxylation [7] was developed by K. Barry Sharpless to use catalytic amounts of OsO 4 along with the stoichiometric oxidant K 3 [Fe(CN) 6]. [1] [2] [8] The reaction is performed in the presence of a chiral auxiliary.

  7. Ene reaction - Wikipedia

    en.wikipedia.org/wiki/Ene_reaction

    In organic chemistry, the ene reaction (also known as the Alder-ene reaction by its discoverer Kurt Alder in 1943) is a chemical reaction between an alkene with an allylic hydrogen (the ene) and a compound containing a multiple bond (the enophile), in order to form a new σ-bond with migration of the ene double bond and 1,5 hydrogen shift.

  8. Asymmetric catalytic oxidation - Wikipedia

    en.wikipedia.org/wiki/Asymmetric_catalytic_oxidation

    The oxidation of alkenes has attracted much attention. Asymmetric epoxidation is often feasible. [4] One named reaction is the Jacobsen epoxidation, which uses manganese-salen complex as a chiral catalyst and NaOCl as the oxidant. The Sharpless epoxidation using chiral N-heterocyclic ligands and osmium tetroxide. Instead of asymmetric ...

  9. Asymmetric nucleophilic epoxidation - Wikipedia

    en.wikipedia.org/wiki/Asymmetric_nucleophilic_ep...

    Chiral auxiliaries, [26] chiral boron enolates, [27] and asymmetric phase transfer catalysis [28] have been used successfully to effect asymmetric induction in the Darzens reaction. (12) Diastereoselective epoxidations of chiral, non-racemic alkenes suffer from the limitation that removal of the auxiliary without disturbing the epoxide is often ...