Nucleophilic Substitution Reactions in the [B 3 H 8 ] - Anion in the Presence of Lewis Acids.

As a result of our study on the interaction between the octahydrotriborate anion with nucleophiles (Nu = THF, Ph 3 P, Ph 2 P-(CH 2 ) 2 -PPh 2 (dppe), Ph 3 As, Et 3 N, PhNH 2 , C 5 H 5 N, CH 3 CN, Ph 2 CHCN)) in the presence of a wide range of Lewis acids (Ti(IV), Hf(IV), Zr(IV), Al, Cu(I), Zn, Mn(II), Co(II) halides and iodine), a number of substituted derivatives of the octahydrotriborate anion [B 3 H 7 Nu] are obtained. It is found that the use of TiCl 4 , AlCl 3 , ZrCl 4 , HfCl 4 , CuCl and iodine leads to the highest product yields. In this case, it is most likely that the reaction proceeds through the formation of an intermediate [B 3 H 7 -HMXn x ], which was detected by NMR spectroscopy. The structures of [Ph 3 P·B 3 H 7 ] and [PhNH 2 ·B 3 H 7 ] were determined by X-ray diffraction.