Recipe for New Diorganostannates, [R₂Sn(OS(O)₂R¹)₄]^2-, Bearing Alkanesulfonate Groups Using Dialkyl Sulfite as the Reagent

A one-pot reaction between di-n-propyl/di-n-butyltin oxide, dialkyl sulfite, and triethylamine or tetra-n-alkylammonium iodide proceeds under ambient conditions (110−120 °C, 20 h) via sulfur-centered Arbuzov rearrangement to afford the corresponding dianionic tetraalkanesulfonato diorganostannates [R₂Sn(OSO₂Me)₄]·2Et₃NMe [R = n-Pr (1), n-Bu (2)] as well as [n-Bu₂Sn(OSO₂R¹)₄]·2R²₄N [R¹ = Me, Et, n-Pr; R² = Et (3, 5, and 7), n-Bu (4, 6, and 8)]. X-ray crystal structures of 2 and 3 reveal a monomeric motif of the dianion, with methanesulfonate groups acting as unidentate ligands. The ¹¹⁹Sn NMR spectral studies suggest the existence of pentacoordinated tin species in solution.