The chemistry of 1,3,2-diazaborolines (2,3-dihydro-1H-l,3,2-diazaboroles)

1,3,2-Diazaborolines (2,3-dihydro-1H-1,3,2-diazaboroles) are at the interface between inorganic, organometallic and organic chemistry. The planar rings with 6 pi -electrons may be regarded as heteroarenes, as evidenced by NMR and photoelectron spectra and confirmed by quantum mechanical calculations. The capability of 1,3,2-diazaborolines to act as eta (5)-ligands adds chemical proof to this idea. High-yield syntheses of 1,3,2-diazaborolines with functional groups at boron have recently become available, providing a rich area of chemistry ranging from substitution processes via borylstannations to their conversion into oxazaborolidines. (C) 2001 Elsevier Science B.V. All rights reserved.