F. Alam, K. Niedenzu
Dec 14, 1982
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0
Influential Citations
11
Citations
Journal
Journal of Organometallic Chemistry
Abstract
Abstract Two 1,3-dimethyl-2-(methylpyrazol-1′-yl)-1,3,2-diazaboracyclopentanes have been prepared. The interaction of such monomeric pyrazol-1-ylboranes containing trigonal boron with pyrazoles has been examined and 1 1 molar addition compounds have been identified and isolated. Labelling experiments support spectroscopic evidence to suggest a mobile bridging hydrogen in the cited adducts at ambient temperature and above. Monomeric 1,3-dimethyl-2-(pyrazol-1′-yl)-1,3,2-diazaboracyclopentane reacts with (dimethylamino)dialkylboranes by an exchange of the pyrazolyl with the dimethylamino group. A cyclic transition state involving a B 2 N 3 ring system is suggested for this process in which the corresponding 2-dimethylamino-1,3,2-diazaboracyclopentane and B -tetraalkylpyrazaboles are the final products. The latter are also found among the reaction products of pyrazole adducts of monomeric pyrazol-1-ylboranes with (dimethylamino)dialkylboranes. The interaction of (dimethylamino)dialkylboranes with pyrazole gives B -tetraalkylpyrazaboles in essentially quantitative yield.