In organophosphorus chemistry, the Kinnear–Perren reaction (sometimes the Clay-Kinnear-Perren reaction) is used to prepare alkylphosphonyl dichlorides (RP(O)Cl2) and alkylphosphonate esters (RP(O)(OR')2). The reactants are alkyl chloride, phosphorus trichloride, and aluminium trichloride as catalyst. The reaction proceeds via the alkyltrichlorophosphonium salt:
- RCl + PCl3 + AlCl3 → AlCl4
Reduction of this trichlorophosphonium intermediate with aluminium powder gives alkyldichlorophosphines (RPCl2).
Partial hydrolysis of the same intermediate gives the alkylphosphonyl dichloride:
- AlCl4 + H2O → RP(O)Cl2 + AlCl3 + 2 HCl
The reaction was first reported by Clay 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.
References
- Svara, J.; Weferling, N.; Hofmann, T. (2008). "Phosphorus Compounds, Organic". 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.