[English name] methyletriphenylphosporane
[Formula] c19h17p
[molecular weight] 276.31
[Ca login No.] [3487-44-3]
[structural formula] ph3p = CH2
[physical properties] white crystal, MP 96 OC. Soluble in ether, THF, DME, benzene, toluene, DMSO. Water or proton solvent will destroy the reagent completely.
[preparation and commodity] the reagent cannot be purchased as a commodity, so the reagent solution must be prepared before use. The reagent is usually prepared by adding a strong base, such as butyl lithium, tert butyl potassium or amino sodium, to methyltriphenylphosphonium bromide suspended in a suitable solvent. In general, methyl triphenylphosphonium bromide is suspended in dry ether or THF, n-butyl lithium is added under the atmosphere of 0 oC and nitrogen, and the reaction is carried out at room temperature for 1 hour. The color changes from yellow to orange, indicating that the ylide reagent has been formed.
[note] the reagent should always be used or treated in nitrogen or argon atmosphere.
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Methylation of aldehydes and ketones the most widely used reagent is Wittig [1] methylene reaction with aldehydes and ketones (formula 1, formula 2) [2,3], the olefin bond and hydroxyl in the molecule are not affected.
A compound similar to acridine can also be methylated by reacting with methylene triphenylphosphine (formula 3) [4].
The substituted 1,3-diene can be prepared by the reaction of p-ylide with the corresponding olefinic aldehyde or ketone (formula 4) [5], and the double bond conjugated with carbonyl is not affected. The diene compounds will continue to be used for Diels alder reaction.
The methylene triphenylphosphine of boron can react with the halogenated boron to form a compound containing B-C bond (formula 5) [6], and a salt (formula 6) [7] can also be formed with the phenolic hydroxyl group.
The methylene in ylide's rearrangement of methylene triphenylphosphine can be salinized with butyl lithium, so that it can react with ketones with certain steric hindrance to make them methylated. α. When β - diketone compounds react with excessive methylene triphenylphosphine, α - Ketol rearrangement can occur and a stable ylide (formula 7) [8] can be obtained. The results of X-ray diffraction show that the phosphorus and oxygen atoms are on the same side of the double bond.
The formation of a chamomile ring system (formula 8) [9] can be obtained by the reaction of a chamomile ring methylenephosphine three phenylphosphine with 2- chlorocycloheptanone three olefine ketone. In the process of reaction, methylene attack 7-h first, then remove the chlorine atom to form a bicyclic system.
The ring opening product (formula 9) [10] can be obtained by the reaction of methylenetriphenylphosphine with lactone and lactone.
reference
1. Wittig, G. Liebigs Ann. Chem., 1953, 580, 44.
2. Koh J. H.; Gagne M. R. Angew. Chem., Int. Ed., 2004, 43, 3459.
3. Gurjar, M. K.; Mohapatra, S.; Phalgune, U. D.; Puranik, V. G.; Mohapatra, D. K. Tetrahedron Lett., 2004, 45, 7899.
4. Rowlands, G. J.; Barnes, W. K. Tetrahedron Lett., 2004, 45, 5347.
5. Bartelt, R. J.; Weisleder, D.; Momany, F. A. Synthesis, 2003, 117.
6. Zheng X.; Wang B. Herberich G. E. Organometallics, 2002, 21, 1949.
7. Broder C. K., Davidson M. G., Forsyth V. T., Howard J. A. K., Lamb S., Mason S. A. Cryst. Growth Design, 2002, 2, 163.
8. Gabbutt C. D.; Hepworth J. D.; Heron B. M.; Jones A. M.; Raper E. S.; Clegg W. Phosphorus Sulfur Silicon Relat. Elem., 1998, 143, 221.
9. Takayasu T.; Nitta M. J. Chem. Soc. Perkin Trans. 1, 1997, 681.
10. Brunel Y.; Rousseau G. Tetrahedron Lett., 1996, 37, 3853.
This paper is from: modern organic synthetic reagents -- properties, preparation and reaction, edited by Hu Yuefei, et al