Tertiary butyl derivatives of tin

Abstract

Several t-butyltin derivatives including the tri-t-butyltin chloride and iodide were synthesized. Experiments designed for the synthesis of tetra-t-butyltin by the reaction of tri-t-butyltin halide with t-butyl-lithium led to the isolation of hexa-t-butyldistannane. On the other hand, other organolithium and Grignard reagents yielded the expected products. A critical study was undertaken to establish the structural requirements in the organotin derivatives for the normal substitution to occur preferentially over the coupling reaction. Two series of monomers of the type R¹₂R²SnX were synthesized for this purpose: Series I, where R¹= Bu^t; R²= Ph, p-MeC₆H₄, PhCH₂, or Buⁿ; and Series II, where R²= Bu^t; R¹= Ph, PhCH₂, or Buⁿ; X = Cl, Br, or I. Coupling was observed with Series I, and Series II yielded the normal products. Halogenation of the tetra-substituted organotin compounds in chloroform was found to be consistent with the following order of reactivity: Ph > PhCH₂ > Bu^t > Buⁿ.