Lawesson's reagent
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| General | |||||||||||||||||||
| Surname | Lawesson's reagent | ||||||||||||||||||
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| Molecular formula | C 14 H 14 O 2 P 2 S 4 | ||||||||||||||||||
| Brief description |
yellow, foul-smelling powder |
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| properties | |||||||||||||||||||
| Molar mass | 404.47 g mol −1 | ||||||||||||||||||
| Physical state |
firmly |
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| Melting point |
221-224 ° C |
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| solubility |
Decomposes in water |
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| As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . | |||||||||||||||||||
Lawesson's reagent is an organic compound containing phosphorus and sulfur and was named after its discoverer, the Swedish chemist Sven-Olov Lawesson .
Manufacturing
Lawesson's reagent is synthesized from phosphorus (V) sulfide and anisole .
use
Lawesson's reagent has been found to be extremely useful in the preparation of thiocarbonyl compounds from carbonyl compounds . It is more reactive than phosphorus (V) sulphide , P 4 S 10 , and at higher temperatures it is sufficiently soluble in organic solvents so that the reactions can be carried out in a homogeneous solution. Lactams can be converted into thiolactams using Lawesson's reagent : phosphine oxides can also be converted into the corresponding phosphine sulfides, enantiomerically pure P-stereogenic compounds react with retention of the configuration.
mechanism
The reagent is in equilibrium with the monomeric form. This reacts with a carbonyl compound in a mechanism similar to that of the Wittig reaction .
See also
Individual evidence
- ↑ a b c Data sheet Lawesson's reagent (PDF) from Merck , accessed April 14, 2005.
- ↑ a b Data sheet Lawesson reagent from Sigma-Aldrich , accessed on April 7, 2011 ( PDF ).
- ↑ Entry on Lawesson's reagent. In: Römpp Online . Georg Thieme Verlag, accessed on September 19, 2014.
- ↑ A. Padwa and MD Danca, Organic Letters 2002 , 715th
- ↑ Małgorzata Kwiatkowska, Grzegorz Krasiński, Marek Cypryk, Tomasz Cierpiał, Piotr Kiełbasiński: Lipase -mediated stereoselective transformations of chiral organophosphorus P-boranes revisited: revision of the absolute configuration of alkoxy (hydroxymethyl) borylphosphine . In: Tetrahedron: Asymmetry . tape 22 , no. 14–15 , July 31, 2011, pp. 1581–1590 , doi : 10.1016 / j.tetasy.2011.08.024 ( sciencedirect.com [accessed June 30, 2016]).
- ^ Portal for organic chemistry .
Web links
- I. Thomsen, K. Clausen, S. Scheibye, and S.-O. Lawesson: Thiation with 2,4-Bis (4-Methoxyphenyl) -1,3,2,4-Dithiaphosphetane 2,4-Disulfide: N-Methylthiopyrrolidone In: Organic Syntheses . 62, 1984, p. 158, doi : 10.15227 / orgsyn.062.0158 ; Coll. Vol. 7, 1990, p. 372 ( PDF ).