Studies on reactivity of in situ generated allylic phosphorus ylides with aldehydes

This account primarily summarizes our recent work on the reactivity of in situ generated allylic phosphorus ylides with aldehydes. Under the mediation of stoichiometric tertiary phosphines, allylic carbonates or allenoates readily undergo highly stereoselective three-component Wittig and vinylogous Wittig olefination reactions through in situ generated allylic phosphorus ylides. These reactions constitute simple and efficient synthetic methods for polysubstituted 1, 3-dienes. Under the catalysis of tertiary phosphines, γ-methyl allenoates chemoselectively undertake several annulations with aldehydes via a key intermediate of allylic phosphorus ylide, providing atom economical synthesis of 5- and 6-membered oxygen heterocycles. By experimental approaches such as deuterium-labeling and NMR monitoring, mechanisms of the above mentioned reactions have also been investigated.