Intermolecular Cyclopropanation of Iodonium Ylides and Electron‐Deficient Alkenes through a Highly Efficient Catalyst‐Free Process

Abstract Catalyst and solvent‐free reactions have attracted great attention from chemists because of their inherent advantages that coincide with the principles of sustainable chemistry and the increasing public awareness of environmental protection. Here, we disclose the first catalyst‐free intermolecular cyclopropanation of phenyliodonium ylides with electron‐deficient alkenes. Full conversion can be achieved at ambient temperature, in the absence of any catalyst, within a short reaction time. Importantly, such reactions work reasonably well in water or even under solvent‐free conditions, which enables a green, convenient and efficient way to synthesize valuable multifunctional vinylcyclopropanes.