Boron Trihalide-Amine Adducts: Direct and Indirect Synthesis

Abstract

Direct combination of boron halides and secondary amines produces, besides adduct, aminodihaloboranes, ammonium salts and bis-(amine) boronium salts. This is avoided by the halogenation of amine-boranes. The synthesis of R₂NHBX₃ is described, where R = CH₃ or C₂H₅, and X = Cl or Br, and of (CH₃NHBI₃. The Cl^[sbnd] and BCl₄ ⁺ salts of [(CH₃)₂NH]₂BCl₂ ⁺ were prepared from [(CH₃)₂NH]₂BH₂ ⁺Cl^[sbnd].