3-Bromo-2-(tert-butylsulfonyl)-1-propene. A multi-coupling reagent. Part 2. <1

3-bromo-2-(tert-butylsulfonyl)-1-propene 1 reacts in good yields with various electrophiles (aldehydes, ketones, nitriles and alkynes) in the presence of zinc metal to give unsaturated sulfones of type 4. These compounds can further react with soft or hard nucleophiles (alkyl-, vinyl-, aryllithium compounds, a nitroparaffin or dimethylmalonate) to yield highly functionnalized sulfones of type 5 which can be readily transformed into enones or into a dienone. Thus sulfone 1 is a versatile multi-coupling reagent which is synthetically equivalent to the $\text{a}{}^2\text{a}{}^{\mathrm{2\prime }}$ synthon 8 and to the $\text{d}{}^2\text{d}{}^{\mathrm{2\prime }}$ synthons 9 and 10.