Tantalum Catalyzed Hydroaminoalkylation for the Synthesis of α- and β‑Substituted <i>N</i>‑Heterocycles

Abstract

Unprotected secondary amines are directly alkylated by C–H functionalization adjacent to nitrogen, thereby opening new routes toward the synthesis of α- and β-alkylated <i>N</i>-heterocycles. α-Alkylated piperidine, piperazine, and azepane products are prepared from heterocycles and alkenes in an atom-economic reaction with excellent regio- and diastereoselectivity. β-Alkylated <i>N</i>-heterocycles are synthesized via a scalable one-pot alkylation/cyclization procedure generating 3-methylated azetidines, pyrrolidines, and piperidines