Controlled heterocyclization/cross-coupling domino reaction of β,γ-allendiols and α-allenic esters: method and mechanistic insight for the preparation of functionalized buta-1,3-dienyl dihydropyrans.

Starting from β,γ-allendiols and α-allenic acetates, a chemo- and regiocontrolled palladium-catalyzed methodology has provided access to enantiopure 3,6-dihydropyrans that bear a buta-1,3-dienyl moiety. Thus, it has been demonstrated for the first time that the preparation of six-membered heterocycles through cross-coupling reactions of two different allenes can be accomplished. These heterocyclization/cross-coupling reactions have been developed experimentally and their mechanisms have additionally been investigated by a computational study.