- Michaelis-Arbuzov reaction
The Michaelis-Arbuzov reaction is the
chemical reaction of a trialkylphosphite and analkyl halide to form aphosphonate .The reaction was discovered by
August Michaelis in1898 [cite journal | author = Michaelis, A.; Kaehne, R. | journal =Berichte | year = 1898 | volume = 31 | pages = 1048 | title = Ueber das Verhalten der Jodalkyle gegen die sogen. Phosphorigsäureester oder O-Phosphine| doi = 10.1002/cber.189803101190] , and greatly explored byAleksandr Arbuzov soon thereafter. [cite journal | author = Arbuzov, A. E. | journal = J. Russ. Phys. Chem. Soc. | year = 1906 | volume = 38 | pages = 687] [cite journal | author = Arbuzov, A. E. | journal = Chem. Zentr. | year = 1906 | volume = II | pages = 1639] This reaction is widely used for the synthesis of various phosphonates,phosphinate s, andphosphine oxide s. Several reviews have been published. [cite journal | author = Arbuzov, B. A. | journal =Pure Appl. Chem. | year = 1964 | volume = 9 | pages = 307–353 | format = | doi = 10.1351/pac196409020307 | title = Michaelis-Arbusow- und Perkow-Reaktionen ] [cite journal | author = Bhattacharya, A. K.; Thyagarajan, G. | journal =Chem. Rev. | year = 1981 | volume = 81 | pages = 415–430 | title = Michaelis-Arbuzov rearrangement | doi = 10.1021/cr00044a004]Reaction mechanism
The Michaelis-Arbuzov reaction is initiated with the SN2 reaction of the
nucleophilic phosphite (1) with theelectrophilic alkyl halide (2) to give a phosphonium intermediate (3). Triaryl phosphites, which are unable to perform the second step of the Michaelis-Arbuzov reaction, have been shown to produce stable phosphonium salts. [cite journal | author = Landuer, S. R.; Rydon, H. N. | journal =J. Chem. Soc. | year = 1953 | pages = 2224
doi = 10.1039/jr9530002224
title = 458. The organic chemistry of phosphorus. Part I. Some new methods for the preparation of alkyl halides] Likewise,aryl andvinyl halides are unreactive towards phosphites.The displaced
halide anion reacts via another SN2 reaction with the phosphonium intermediate to give the desired phosphonate (4) and another alkyl halide (5). When chiral phosphonium intermediates are produced, it has been shown the halide substitution proceeds with inversion of configuration, as expected by a SN2 reaction. [cite journal | author = Gerrard, W.; Green, W. J. | journal = J. Chem. Soc. | year = 1951 | pages = 2550
doi = 10.1039/jr9510002550
title = 568. Mechanism of the formation of dialkyl alkylphosphonates]As a general guideline, the reactivity of the organic halide (2) can be listed as follows: (from most reactive to least reactive) RCOX > RCH2X > RR'CHX >> RR'R"CX
and
RI > RBr > RCl
The reaction of α-bromo- and α-chloroketones with phosphites yields a vinyl phosphate instead of an alkyl phosphonate – the
Perkow reaction . α-Iodoketones do, in fact, give the a phosphonate. [cite journal | author = Jacobsen, H. I.; Griffin, M. J.; Preis, S.; Jensen, E. V. | journal =J. Am. Chem. Soc. | year = 1957 | volume = 79 | pages = 2608
doi = 10.1021/ja01567a067
title = Phosphonic Acids. IV. Preparation and Reactions of β-Ketophosphonate and Enol Phosphate Esters] Other methods of producing β-ketophosphonates have been developed. [OrgSynth | author = Nagata, W.; Wakabayashi, T.; Hayase, Y. | collvol = 6 | collvolpages = 448 | year = 1988 | prep = cv6p0448 | title = Diethyl 2-(cyclohexylamino)vinylphosphonate]References
ee also
*
Perkow reaction External links
* Ford-Moore, A. H.; Perry, B. J. "
Organic Syntheses ", Coll. Vol. 4, p.325 (1963); Vol. 31, p.33 (1951). ( [http://www.orgsyn.org/orgsyn/prep.asp?prep=cv4p0325 Article] )
* Davidsen, S. K.; Phllips, G. W.; Martin, S. F. "Organic Syntheses ", Coll. Vol. 8, p.451 (1993); Vol. 65, p.119 (1987). ( [http://www.orgsyn.org/orgsyn/prep.asp?prep=cv8p0451 Article] )
* Enders, D.; von Berg, S.; Jandeleit, B. "Organic Syntheses ", Coll. Vol. 10, p.289 (2004); Vol. 78, p.169 (2002). ( [http://www.orgsyn.org/orgsyn/prep.asp?prep=v78p0169 Article] )
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