Oxidative selenofunctionalization of allenes: Convenient access to 2-(phenylselanyl)-but-2-enals and 4-oxo-3-(phenylselanyl)pent-2-enoates

The controlled preparation of two types of α-seleno-α,β-unsaturated carbonyls, namely, α-selenoenals and α-selenoenones, has been accomplished directly from allenes through metal-free oxidative selenofunctionalization reactions. The decisive role of organoselenium and 1-fluoropyridinium reagents has been disclosed. The divergent reactivity due to the presence or absence of an ethoxycarbonyl moiety at the allene end has also been studied. A tentative pathway implying selective electrophilic addition of the selenium reagent to the allene moiety followed by adventitious water attack and concomitant oxidation has been proposed.Financial support for this work from MINECO and FEDER (projects CTQ2015-65060-C2-1-P and CTQ2015-65060-C2-2-P) is gratefully acknowledged. M. T.-P. thanks CAM and FEDER (YEI) for a predoctoral contract.We acknowledge support of the publication fee by the CSIC Open Access Support Initiative through its Unit of Information Resources for Research (URICI)Peer Reviewe