Regiodivergent α- and β-Functionalization of Saturated <i>N</i> -Heterocycles by Photocatalytic Oxidation
Jonas W. Rackl, Alexander F. Müller, Antonia Profyllidou, Helma Wennemers
Abstract
High Resolution Image Download MS PowerPoint Slide Synthetic methods that provide access to two different types of products via a central intermediate are highly valuable but difficult to establish. Here, we present a photocatalytic, regiodivergent method for the functionalization of saturated N -heterocycles at either the α- or the β-position. A t -butyl carbamate (Boc)-stabilized iminium ion serves as the key intermediate en route to either α-hydroxylation or β-elimination, depending on the choice of base. The operationally simple procedures use a readily available flavin-based catalyst and reagents, aqueous media and do not require metals. Combined with facile downstream derivatization, the regiodivergent reaction gives rapid access to a large set of functionalized piperidines, molecules that are highly sought-after for the synthesis of pharmaceuticals and agrochemicals.