Alkynyl cyclopropanes in organic synthesis

The data on the reactions of various classes of functionalized alkynyl cyclopropanes that proceed with simultaneous participation of triple bond, three-membered ring, and functional group at a cyclopropane ring are systematized. The syntheses of polysubstituted and fused furans and indoles based on electrophile-induced and catalytic transformations of alkynyl cyclopropyl carbonyl compounds and their derivatives are considered separately. The methods for isomerization of 1-alkynyl cyclopropanols and their ethers to 3-methylenecyclobutanones are described. Information on the reactions of other types of alkynyl cyclopropanes containing one or more functional groups at three-membered ring leading to different acyclic, carbo-, and heterocyclic compounds is given. Transformations of alkynyl cyclopropanes lacking the functional groups, which simultaneously involved the cyclopropane ring and the alkynyl fragment, are also discussed.