Palladium-catalyzed dehydrostannylation of n-alkyltin trichlorides

Abstract

[Pd(PPh₃)₄] catalyzes the dehydrostannylation of n-alkyltin trichlorides into HSnCl₃(THF)_n and isomers of the corresponding alkene. The reaction mechanism involves oxidative addition of the Sn–C bond followed by β-H elimination from the resulting n-alkylpalladium trichlorostannyl species. Rate-determining reductive elimination of HSnCl₃ from cis-[PdH(SnCl₃)(PPh₃)₂] completes the catalytic cycle. Organotin trichlorides without β-H atoms either do not react or undergo thermal disproportionation. These results are relevant to understand some of the problems associated with the use of monoalkyltin compounds as coupling partner in Stille-type cross-coupling reactions as well as with the catalytic hydrostannylation of 1-alkenes to monoalkyltin trichlorides.