Transition Metal-free gem-difluorocyclopropanation of Alkenes with CF₃SiMe₃−NaI System: a Recipe for Electron-deficient Substrates

Reaction of various electron‐deficient alkenes, as well as functionalized styrene derivatives with CF₃SiMe₃−NaI system is studied. Relative reactivity of the substrates is established. It is shown that many α,β‐unsaturated esters can be difluorocyclopropanated efficiently under “slow addition protocol” conditions, which provides access to mono‐ and spirocyclic gem‐difluorocyclopropyl‐substituted carboxylic acids with good yields (36–79% for two steps) on up to 100 g scale.