Direct Regio-, Diastereo-, and Enantioselective Vinylogous Michael Addition of Prochiral 3-Alkylideneoxindoles to Nitroolefins

3-Alkylidene-2-oxindoles represent a simple, yet enabling sub-family of indole alkaloids, and their ability to react as electron-poor acceptors has largely been investigated. In contrast, their utility as nucleophilic or pronucleophilic synthons remains elusive. In this context, this article describes the successful execution of the direct, organocatalytic asymmetric Michael addition of prostereogenic 3-alkylidene oxindoles to nitroolefins, through which a variety of ?-substituted alkylidene oxindoles chiral at both the ?- and ?-carbon sites were assembled with excellent stereoselectivity and without olefin isomerization or stereochemical ablation.