Hydroarylation of Alkenes by protonation/Friedel-Crafts Trapping – HFIP-Mediated Access to Per-Aryl Quaternary Stereocentres

<div> <p>Upon treatment with a combination of HFIP and a strong Brønsted acid, alkenes behave as Brønsted bases and protonate to give carbocations which can be trapped by electron rich arenes. The reaction constitutes a Friedel-Crafts (FC) hydroarylation which proceeds with Markovnikov selectivity and is orthogonal to traditional metal catalyzed processes. The products contain polyarylated quaternary carbon atoms which are difficult to obtain <i>via</i> alternative methods. Intermolecular transfer hydrogenation and hydrothiolation are also demonstrated. </p> </div>