Halogenated Donor–Acceptor Cyclopropanes as Donor–Acceptor Cyclopropene Surrogates

Abstract Herein we report (3+2)‐cycloaddition reactions of halogenated donor–acceptor cyclopropanes (HDACs) as surrogates for donor–acceptor cyclopropenes. Upon reaction with a variety of 2π‐components, cycloaddition followed by elimination generates the unsaturated five‐membered ring products. A series of HDACs were shown to be effective in reactions with thioketones. Five further cycloaddition reactions were used to showcase the broad applicability of these donor–acceptor cyclopropene surrogates. Kinetic studies allowed the proposal of a plausible mechanism for this reaction.