Oxidative addition reactions of dicyclopentadienyltin(II) and of tin(II) bis(acetylacetonate) with organic halides. The preparation of compounds of the type RSn(acac)2X

Oxidative addition reactions of tin(II) bis(acetylacetonate) with organic halides provide a route to new monoorganotin(IV) bis(acetylacetonate) halides. Dicyclopentadienyltin(II) undergoes oxidative addition with methyl iodide, diiodomethane and ethyl bromoacetate, but with allyl bromide, benzyl bromide and triphenylmethyl bromide carbon—carbon coupling reactions and the formation of the corresponding cyclopentadienyltin(II) halide take place. Some of the reactions are accelerated by light. NMR spectroscopic data show that the RSn(acac)₂X compounds have a cis-configuration. The compounds YCH₂Sn(acac)₂X (e.g. Y = I, CHCH₂, COOEt) provide the first examples of diastereo-topic non-equivalence of methylene protons in organotin compounds containing a hexacoordinate chiral tin centre.