Electrophilic Ring Opening of Small Heterocycles

Small heterocycles, such as epoxides, aziridines, and ox­etanes are among the most useful building blocks in organic synthesis. Through electrophilic ring opening of these molecules, various electrophilic functional groups can be installed, which cannot be achieved via classic nucleophilic ring-opening reactions. In this review, the developments of electrophilic ring opening of small heterocycles are surveyed and organized according to the types of metal promoters. 1 Introduction 2 Electrophilic Ring Opening of Small Heterocycles Using Stoichiometric Metals 2.1 Lithium-Mediated Electrophilic Ring Opening of Epoxides and Oxetanes 2.2 Chromium-Mediated Electrophilic Ring Opening of Vinyl Epoxides 2.3 Tin-Mediated Electrophilic Ring Opening of Vinyl Epoxides 2.4 Samarium-Mediated Electrophilic Ring Opening of Vinyl and Alkynyl Epoxides 2.5 Titanium-Mediated Electrophilic Ring Opening of Epoxides 2.6 Platinum, Palladium, and Nickel-Mediated Electrophilic Ring Opening of 1,1-Dimethyl Ethylene Oxide 3 Catalytic Electrophilic Ring Opening of Small Heterocycles 3.1 Titanium-Catalyzed Electrophilic Ring Opening of Epoxides 3.2 Palladium-Catalyzed Electrophilic Ring Opening of Vinyl and Alkynyl Small Heterocycles 3.3 Iron-Catalyzed Electrophilic Ring Opening of Oxetanes 3.4 Scandium-Catalyzed Electrophilic Ring Opening of Vinyl Epoxides 3.5 Iridium-Catalyzed Electrophilic Ring Opening of 2-Methyl 2-Vinyl­oxiranes 3.6 Nickel-Catalyzed Electrophilic Ring Opening of Epoxides and Aziridines 3.7 Nickel–Titanium-Cocatalyzed Electrophilic Ring Opening of Epoxides 4 Summary