Efficient synthesis and NMR data ofN- orB-substituted borazines

The thermolysis of borane-primary amine complexes RNH2.BH3 was reexamined. Excellent yields of N-substituted borazines were obtained at 200°C, when R is an alkyl group, and at 120°C for R = Ph. B-alkyl, vinyl, and alkynyl borazines were easily prepared in good to excellent yields by ammonolysis of bis(diisopropylamino)organoboranes at temperatures above 95°C. The 1H, 13C, and 15N or 14N NMR data for all borazines prepared are reported for the first time.