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. Se ha desarrollado un nuevo proceso de heterociclación‐acoplamiento cruzado de β,γ‐alenildioles y ésteres α‐alénicos que ha conducido a la obtención de dihidropiranos enantiopuros diferentemente sustituídos. Se ha comprobado a su vez, que este proceso ocurre con total regio‐ y quimioselectividad, así como con conservación de la integridad estereoquímica. Estas reacciones de heterociclación‐acoplamiento se han desarrollado experimentalmente y sus mecanismos se han investigado por métodos computacionales. Domino effect: Chemo‐ and regiocontrolled palladium‐catalyzed cross‐coupling of two different allenes, namely, β,γ‐allendiols and α‐allenic acetates, can occur in a heterocyclization/cross‐coupling domino sequence to provide access to enantiopure 3,6‐dihydropyrans that bear a buta‐1,3‐dienyl moiety (see scheme). The mechanism has been investigated by a computational study.