The Appel reaction is an organic reaction that converts an alcohol into an alkyl chloride using triphenylphosphine and carbon tetrachloride.[1] The use of carbon tetrabromide or bromine as a halide source will yield alkyl bromides, whereas using carbon tetraiodide, methyl iodide or iodine gives alkyl iodides. The reaction is credited to and named after Rolf Appel,[2] it had however been described earlier.[3] The use of this reaction is becoming less common, due to carbon tetrachloride being restricted under the Montreal protocol.
The Appel reaction
Drawbacks to the reaction are the use of toxic halogenating agents and the coproduction of organophosphorus product that must be separated from the organic product.[4] The phosphorus reagent can be used in catalytic quantities.[5][6] The corresponding alkyl bromide can also be synthesised by addition of lithium bromide as a source of bromide ions. A greener, more sustainable Appel reaction, free from chlorinated solvents and requiring only a catalytic amount of phosphine reagent, has also been reported.[7]
Catalytic Appel reaction scheme
^Rolf Appel (1975). "Tertiary Phosphane/Tetrachloromethane, a Versatile Reagent for Chlorination, Dehydration, and P-N Linkage". Angewandte Chemie International Edition in English. 14 (12): 801–811. doi:10.1002/anie.197508011.
^"Chemie". Archived from the original on 2019-08-11. Retrieved 2011-08-24.
^Downie, I; Holmes, J; Lee, J (1966). "Preparation of Alkyl Chlorides Under Mild Conditions". Chemistry and Industry (22): 900. ISSN 0009-3068.
^Cadogan, J, ed. (1979). Organophosphorus Reagents in Organic Synthesis. London: Academic Press. ISBN 978-0-12-154350-1.
^Denton, Ross; An, Jie; Adeniran, Beatrice; Blake, Alexander; Lewis, William; Poulton, Andrew (2011). "Catalytic Phosphorus(V)-Mediated Nucleophilic Substitution Reactions: Development of a Catalytic Appel Reaction". Journal of Organic Chemistry. 76 (16): 6749–6767. doi:10.1021/jo201085r. PMID 21744876.
^van Kalkeren, Henri A.; Leenders, Stefan H. A. M.; Hommersom, C. (Rianne) A.; Rutjes, Floris P. J. T.; van Delft, Floris L. (2011). "In Situ Phosphine Oxide Reduction: A Catalytic Appel Reaction". Chemistry: A European Journal. 17 (40): 11290–11295. doi:10.1002/chem.201101563. hdl:2066/91927. PMID 21882274.
^Jordan, Andrew; Denton, Ross M.; Sneddon, Helen F. (10 February 2020). "Development of a More Sustainable Appel Reaction". ACS Sustainable Chemistry & Engineering. 8 (5): 2300–2309. doi:10.1021/acssuschemeng.9b07069. S2CID 213147247.
The Appelreaction is an organic reaction that converts an alcohol into an alkyl chloride using triphenylphosphine and carbon tetrachloride. The use of...
as the hydrogen acceptor, and the PPh3 is oxidized to OPPh3. In the Appelreaction, a mixture of PPh3 and CX4 (X = Cl, Br) is used to convert alcohols...
province of Gelderland Appel (surname), including list of people with the surname Appelreaction, an organic chemical reaction A fencing term Appell,...
chemistry, carbon tetrachloride serves as a source of chlorine in the Appelreaction. Carbon tetrachloride made from heavy chlorine-37 has been used in the...
always of a cyclical nature. A novel variant of the Appelreaction has been noted for sulfenamides. Reaction of o-nitrobenzenesulfenamide with PPh3 and CCl4...
expected reactions. It can be converted to the tosylate, which is a precursor to the chloride. Geranyl chloride also arises by the Appelreaction by treating...
convenient, because the byproducts are gaseous. Alternatively, the Appelreaction can be used: Alkyl chlorides are versatile building blocks in organic...
CH3COCl + C6H5CO2H}}} Other methods that do not form HCl include the Appelreaction: RCO 2 H + Ph 3 P + CCl 4 ⟶ RCOCl + Ph 3 PO + HCCl 3 {\displaystyle...
structure. In combination with triphenylphosphine, CBr4 is used in the Appelreaction, which converts alcohols to alkyl bromides. Similarly, CBr4 is used...
Chemistry at Bonn University in Bonn, when he developed the Appelreaction. For his discovery, Appel received the Liebig Medal. In 1986, he retired from the...
converted in and to iodide, by a mechanism similar to the Appelreaction. In an Appelreaction, carbon tetrachloride is used to generate alkyl chlorides...
triiodide). One family of named reactions relies on the deoxygenating effect of triphenylphosphine. In the Appelreaction, the reagent is tetrahalomethane...
Christiaan Karel Appel (pronounced [ˈkrɪstijaːn ˈkaːrəl ˈɑpəl] ; 25 April 1921 – 3 May 2006) was a Dutch painter, sculptor, and poet. He started painting...
propanol is a popular precursor amino alcohol. Modification of the Appelreaction allows for the synthesis of oxazoline rings. This method proceeds under...
salts with the general structure PR4+X−. This property is used in the Appelreaction for converting alcohols to alkyl halides. Phosphines are easily oxidized...
Combat stress reaction (CSR) is acute behavioral disorganization as a direct result of the trauma of war. Also known as "combat fatigue", "battle fatigue"...
Lotion". Archived from the original on 2007-06-19. Retrieved 2007-07-19. Appel, L.M. Ohmart; Sterner, R.F. (1956). "Zinc oxide: A new, pink, refractive...
Appelreaction which caused an elimination reaction (loss of HBr) to cyclopropane 3.12. Treatment with hydrochloric acid formed ketone 3.13, reaction...
April 2023). "Nitrites et jambons "cancérogènes": nouvelle victoire en appel de Yuka contre un industriel de la charcuterie" [Nitrites and "carcinogenic"...
Network in the United States on April 14, 1996. It was written by Richard Appel, David X. Cohen, Jonathan Collier, Jennifer Crittenden, Greg Daniels, Brent...
direct electric current (DC) to drive an otherwise non-spontaneous chemical reaction. Electrolysis is commercially important as a stage in the separation of...
two known sets of fusion reactions by which stars convert hydrogen to helium, the other being the proton–proton chain reaction (p–p cycle), which is more...
Global Information
