Organoborazines. Part 2. Synthesis of alkenyltriborazines

Abstract

A series of unsymmetrically B-substituted N-methyl and N-phenyl borazines R³(R²)₂B₃N₃(R¹)₃(R³= vinyl, allyl, or p-vinylphenyl; R²= methyl or phenyl; R¹= methyl or phenyl) were prepared by substitution reactions of Cl₃B₃N₃Me₃ and H₃B₃N₃Ph₃ using Grignard reagents. Substituent exchange processes in these reactions were monitored by gas chromatography-mass spectrometry. These compounds were prepared in moderate yields and characterized by a combination of i.r. spectroscopy, ¹H, ¹³C, and ¹¹B n.m.r. spectroscopy, mass spectrometry, and elemental analysis. N.m.r. evidence for the existence of mesomeric interactions of the borazines with the vinyl substituent and lack of such interactions with the p-vinylphenyl substituent was obtained.