Base-catalyzed regio- and stereoselective addition of isatins to trifluoromethylated alkynes for preparation of <i>N</i> -alkenylisatins

Direct addition of isatins to trifluoromethylated internal alkynes was developed under inorganic base catalysis with simple, mild, and environmentally benign conditions. A series of intended <i>N</i>-alkenylisatins was readily assembled with good functional group compatibility and diversity. Meanwhile, exclusive regio- and stereo-selectivities were achieved to provide the β-adducts with <i>Z</i> configuration only. Taking advantage of its intrinsic versatile reactivity, the <i>N</i>-alkenylisatin product was transformed into useful 2-phenyl-3-(trifluoromethyl)quinoline-4-carboxylates <i>via</i> one-step late-stage derivatization. In addition, a set of control experiments was designed and implemented to shed light on the possible reaction mechanism.