Reduktion von Butyl-und Phenylantimon(III)bromiden sowie von t-Butylantimon(III)chloriden mit Magnesium in Gegenwart von Trimethylchlorsilan: Konkurrenz von Sb-Sb-und Sb-Si-Verknüpfung / Reduction of Butyl-and Phenylantimony(III) Bromides and of t-Butylantimony(III) Chlorides with Magnesium in the Presence of Trimethylchlorosilane: Competition of Sb-Sb and Sb-Si Coupling

Abstract

Butylantimony(III) bromides react with Mg in tetrahydrofuran (THF) even in presence of Me3SiCl exclusively with Sb-Sb-coupling: Starting from Bu2SbBr, Bu2SbSbBu2 is formed and BuSbBr2 is reduced to (BuSb)x. Sb-Si-coupling dominates in the reactions of Ph2SbBr or t-Bu2SbCl with Mg/Me3SiCl/THF yielding Ph2SbSiMe3 or t-Bu2SbSiMe3. Both Sb-Sb- and Sb-Si-coupling reactions are observed, when PhSbBr2 reacts with Mg and Me3SiCl yielding PhSb(SiMe3)2 and (PhSb)x. The same reactants can also form the distibanes Ph2(SiMe3)2Sb2 and Ph(SiMe3)3Sb2. The reaction of t-BuSbCl2 with Mg/Me3SiCl yields the stibines t-BuSb(SiMe3)2 and Sb(SiMe3)3 together with (t-BuSb)4. In the reactions of t-BuSbCl2 or PhSbBr2 the ratio of Sb-Sb- and Sb-Si-coupling can be strongly influenced by using different reaction conditions.