Enol and Ynol Surrogates: Promising Substrates for Hypervalent Iodine Chemistry

In numerous iodine(III)-mediated methodologies that involve ketone compounds, the enol tautomer is expected to be the reactive species. In this context, the exploration of enol and ynol surrogates as substrates is of great interest. Activated pi-systems have been shown to exhibit interesting and highly exploitable behavior toward hypervalent iodine reagents. This has led to the development of numerous useful oxidative transformations. Enamines, enamides, enol derivatives, haloalkenes, and haloalkynes are all enol or ynol surrogates that are reactive towards the most popular iodanes and iodonium salts. This Focus Review will describe past and on-going research involving these substrates to gain insight into the similarities and disparities observed in their reactivity profiles.