Sterically hindered organotin compounds. Part 1. Synthesis and reaction chemistry of tris(trimethylsilyl)methyltin(IV) derivatives. X-Ray crystal structures of Sn(CH2Ph)2[C(SiMe3)3](OSiMe3) and Sn(CH2Ph)2[C(SiMe3)3][CH2CHC(SiMe3)2]

Abstract

Halogen cleavage reactions of SnR_nPh_4–n have been explored as routes to sterically hindered organotin halides SnR_nX_{4 –n}[R = hindered alkyl group: Prⁱ, CH₂CMe₂Ph, or C(SiMe₃)₃; n= 1 or 2]. While the method works well for simple alkyl groups reaction of X₂(X = Cl or Br) with Sn[C(SiMe₃)₃]Ph₃ usually forms Sn[C(SiMe₃)₃]PhX₂. The compound Sn[C(SiMe₃)₃]X₃ can be formed when FeBr₃ is added as catalyst. Reaction of Sn(CH₂Ph)₂[C(SiMe₃)₃]Cl with Br₂ yields Sn(CH₂C₆H₄Br-p)₂[C(SiMe₃)₃]Br, while the same compound in reaction with aqueous HBr yields both Sn(CH₂Ph)₂[C(SiMe₃)₃](OSiMe₃) and Sn(CH₂Ph)₂[C(SiMe₃)₃][CH₂CHC(SiMe₃)₂]. The identity of the latter two compounds has been confirmed by X-ray crystallography.