Some Reactions of Dimethylphosphono- Substituted Diazoalkanes. (MeO)2P(O)CR Transfer to Olefins and 1,3-Dipolar Additions of (MeO)2P(O)C(N2)R1

Abstract

The dimethylphosphono-substituted diazoalkanes PhC(N2)P(O)(OMe)2 and N2CHP(O)(OMe)2 have been prepared, the first via the tosylhydrazone route, and the second by diazotization of the amine, and both could be isolated as the pure compounds. Their copper-catalyzed decomposition in the presence of olefins serves well in the preparation of dimethylphosphono-substituted cyclopropanes. Dimethyl a-diazobenzylphosphonate was found to react with triphenylphosphine to give the phosphazine and to methylenate mercuric chloride. 1,3-Dipolar addition to acrylonitrile, methyl vinyl ketone, and diethyl maleate gave stable Δ2-pyrazolines, and 1,3-dipolar additions to two vinylphosphonate esters were carried out in such a manner that the pyrazolines were decomposed to the cyclopropanes. Protolysis reactions of both diazo compounds are described and dimethyl diazomethylphosphonate could be metalated with mercury(II) and silver (I) acetylacetonates. © 1971, American Chemical Society. All rights reserved.