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  2. Wittig reagents - Wikipedia

    en.wikipedia.org/wiki/Wittig_reagents

    The alkylphosphonium salt is deprotonated with a strong base such as n-butyllithium: [Ph 3 P + CH 2 R]X − + C 4 H 9 Li → Ph 3 P=CHR + LiX + C 4 H 10. Besides n-butyllithium (n BuLi), other strong bases like sodium and potassium t-butoxide (t BuONa, t BuOK), lithium, sodium and potassium hexamethyldisilazide (LiHMDS, NaHMDS, KHDMS, where HDMS = N(SiMe 3) 2), or sodium hydride (NaH) are also ...

  3. Methylenetriphenylphosphorane - Wikipedia

    en.wikipedia.org/wiki/Methylenetriphenylphosphorane

    Crystallographic characterization of the colourless ylide reveals that the phosphorus atom is approximately tetrahedral. The PCH 2 centre is planar and the P=CH 2 distance is 1.661 Å, which is much shorter than the P-Ph distances (1.823 Å). [5] The compound is usually described as a combination of two resonance structures: Ph 3 P + CH 2 − ...

  4. Methoxymethylenetriphenylphosphorane - Wikipedia

    en.wikipedia.org/wiki/Methoxymethylenetriphenyl...

    This reagent reacts with a ketone or aldehyde in a Wittig reaction to give an enol ether, which can be converted to the aldehyde by acid-induced hydrolysis. The initial report of the reaction demonstrated its use on the steroid tigogenone. It was later used in the Wender Taxol total synthesis and the Stork quinine total synthesis.

  5. Wittig reaction - Wikipedia

    en.wikipedia.org/wiki/Wittig_reaction

    The Wittig reaction or Wittig olefination is a chemical reaction of an aldehyde or ketone with a triphenyl phosphonium ylide called a Wittig reagent. Wittig reactions are most commonly used to convert aldehydes and ketones to alkenes. [1] [2] [3] Most often, the Wittig reaction is used to introduce a methylene group using ...

  6. Carbomethoxymethylenetriphenylphosphorane - Wikipedia

    en.wikipedia.org/wiki/Carbomethoxymethylenetri...

    It undergoes a Wittig reaction. [1] It is used in the Vitamin B12 total synthesis. Production

  7. Aza-Wittig reaction - Wikipedia

    en.wikipedia.org/wiki/Aza-Wittig_reaction

    [1] [3] There exists solid-supported modifications of the reaction. [4] [1] [5] Similar to the Wittig reaction, the reaction suffers from issues with triphenylphosphine oxide by-product removal. Such an issue is mitigated via catalytic aza-Wittig-reactions, some of which entail elements other than phosphorus, like arsenic and tellurium [5] [6].

  8. Petasis reagent - Wikipedia

    en.wikipedia.org/wiki/Petasis_reagent

    Unlike the Wittig reaction, the Petasis reagent can react with a wide range of aldehydes, ketones and esters. [4] The Petasis reagent is also very air stable, and is commonly used in solution with toluene or THF. The Tebbe reagent and the Petasis reagent share a similar reaction mechanism.

  9. Sodium bis(trimethylsilyl)amide - Wikipedia

    en.wikipedia.org/wiki/Sodium_bis(trimethylsilyl...

    These carbene reagents add to alkenes to give substituted cyclopropanes and cyclopropenes. [4] To deprotonation of phosphonium salts, generating Wittig reagents. NaHMDS deprotonates compounds containing weakly acidic O–H, S–H, and N–H bonds. These include cyanohydrins and thiols. [5]

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