Syntheses and structures of [Me2Si{As(PtBu)3}2] and [(CyP)3SiMe2] (Cy = cyclohexyl, C6H11)

The reaction of the anion [(tBuP)3As]− (1) with Me2SiCl2 results in nucleophilic substitution of the Cl− anions, giving the di- and mono-substituted products [Me2Si{As(PtBu)3}2] (3a) and [Me2Si(Cl){As(PtBu)3}] (3b). Analogous reactions of the pre-isolated [(CyP)4As]− anion (2) (Cy = cyclohexyl) with Me2SiCl2 produced mixtures of products, from which no pure materials could be isolated. However, reaction of 2 [generated in situ from CyPHLi and As(NMe2)3] gives the heterocycle [(CyP)3SiMe2] (4). The X-ray structures of 3a and 4 are reported.