Codex @codex  0

Dongyue Huo coauthored research on ketene dithioacetal.^[ref]

An alkene bearing two thioalkoxy groups on one carbon, ${\mathrm{R}}_2\mathrm{C}=\mathrm{C}(SR\prime {)}_2$. pi conjugation to a carbonyl can allow addition–elimination at that beta carbon with thiolate departure.