In organophosphorus chemistry, the Kinnear–Perren reaction (sometimes the Clay-Kinnear-Perren reaction) is used to prepare alkylphosphonyl dichlorides (RP(O)Cl2) and alkyl phosphonate esters (RP(O)(OR')2). [1] The reactants are alkyl chloride, phosphorus trichloride, and aluminium trichloride as catalyst. [2] The reaction proceeds via the alkyltrichloro phosphonium salt:
- RCl + PCl3 + AlCl3 → [RPCl3+AlCl4−
Reduction of this trichlorophosphonium intermediate with aluminium powder gives alkyldichlorophosphines (RPCl2).
Partial hydrolysis of the same intermediate gives the alkylphosphonyl dichloride:
- [RPCl3+AlCl4− + H2O → RP(O)Cl2 + AlCl3 + 2 HCl
The reaction was first reported by Clay [3] and expanded upon by Kinnear and Perren, who demonstrated that the four chlorinated methanes (CH4−xClx) give the corresponding CH3-, CH2Cl-, CHCl2-, and CCl3-substituted derivatives. They also demonstrated workup with hydrogen sulfide to give the alkylthiophosphoryl dichlorides. [4]
References
- ^ Svara, J.; Weferling, N.; Hofmann, T. (2008). "Phosphorus Compounds, Organic". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi: 10.1002/14356007.a19_545.pub2. ISBN 978-3-527-30673-2..
- ^ Rachel Waschbüsch; John Carran; Angela Marinetti; Philippe Savignac (1997). "The Synthesis of Dialkyl α-Halogenated Methylphosphonates" (PDF). Synthesis. 1997 (7): 727–743. doi: 10.1055/s-1997-1417.
- ^ Clay, John P. (June 1951). "A New Method for the Preparation Of Alkane Phosphonyl Dichlorides". The Journal of Organic Chemistry. 16 (6): 892–894. doi: 10.1021/jo01146a010.
- ^ A. M. Kinnear; E. A. Perren (1952). "Formation of Organo-Phosphorus Compounds by the Reaction of Alkyl Chlorides with Phosphorus Trichloride in the Presence of Aluminium Chloride". J. Chem. Soc.: 3437–3445. doi: 10.1039/JR9520003437.