Synthesis, characterization and primary evaluation of the synthetic efficiency of supported vinyltins and allyltins

Supported vinyltins and allyltins grafted to an insoluble cross-linked polystyrene matrix were prepared using methods usually employed in solution, like hydrostannylation of alkynes, transmetallation of a tin halide with organomagnesium or organozinc reagents, and substitution of an allyl halide by a supported stannylanion or SN2′ substitution of a supported β-stannylacrolein acetal by cyanocopper reagents in the presence of boron trifluoride etherate. The insoluble grafted organotin reagents were analysed by HRMAS NMR, allowing an unambiguous assignment of their isomeric distribution or the identification of side products. When involved in Stille cross-coupling reactions (vinyltins) or in addition on aldehydes (allyltins), these supported reagents exhibit similar reactivity and similar stereoselectivity when compared to the tributyltin analogues, with the advantage to prevent problems due to the contamination by tin residues.