Bamford-Stevens reaction
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The Bamford-Stevens reaction is a chemical reaction whereby treatment of tosylhydrazones with strong base gives alkenes.<ref name="bamford1952">Bamford, W. R.; Stevens, T. S. (1952). "The decomposition of toluene-p-sulfonylhydrazones by alkali". J. Chem. Soc.: 4735–4740. DOI:10.1039/JR9520004735.</ref><ref name="shapiro1976">Shapiro, R. H. (March 1976). “Alkenes from Tosylhydrazones”, Organic Reactions, 405–507. ISBN 047119624X.</ref><ref name="adlington1983">Adlington, R. M.; Barrett, A. G. M. (1983). "Recent applications of the Shapiro reaction". Acc. Chem. Res. 16 (2): 55–59. DOI:10.1021/ar00086a004.</ref> The usage of aprotic solvents gives predominantly Z-alkenes, while protic solvent gives a mixture of E- and Z-alkenes.
The treatment of tosylhydrazones with alkyl lithium reagents is called the Shapiro reaction.
[edit] Reaction mechanism
The first step of the Bamford-Stevens reaction is the formation of the diazo compound 3.<ref name="creary1986">Creary, X. (1986). "Tosylhydrazone salt pyrolises: phenyldiazomethanes". Organic Syntheses 64: 207. (also in the Collective Volume (1990) 7:438 (PDF))</ref>
In protic solvents, the diazo compound 3 decomposes to the carbenium ion 5.
In aprotic solvents, the diazo compound 3 decomposes to the carbene 7.
[edit] References
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