The SO2-insertion into tin-carbon bonds of mixed tetraorganostannanes, R3SnR′ (R=C6H5, CH3; R'=CH3, C6H5, CH2=CH), is determined by the nucleophilicity of the organic residue attached to metal and shows a decreasing rate in the order aryl > alkenyl > alkyl. A correlation to Taft’s constant is given. The behaviour of triphenylvinyltin toward sulfur dioxide is in good agreement with this rule, as the insertion of one or two moles of SO2 takes place only into Sn—C6H5 bond.
The SO2-insertion into the tin-carbon bond of mixed tetraorganostannanes, R3SnR’ (R = alkyl, R’ = aryl, and vice versa), is determined by the nucleophilicity of the organic residue attached to metal, the ease of cleavage decreasing in the order aryl > alkenyl ⪢ alkyl. As has been proved by chemical and spectroscopic methods the reaction of triphenylmethyltin with liquid sulfur dioxide follows the above rule: Sn—CH3 bond remains unattacked, but one or two moles of SO2 can be inserted into Sn—C6H5 bonds depending on experimental conditions.