Photoredox-Catalyzed Deaminative Alkylation via C-N Bond Activation of Primary Amines.

Abstract

Primary amines are often cheap, naturally occurring, and chemically diverse starting materials. For these reasons, deaminative functionalization of amines has emerged as an important area of research. Recent advances in C-N activation transform simple α-1° and α-2° amines into alkylating reagents via Katritzky pyridinium salts. We report a complementary method that activates sterically encumbered α-3° primary amines through visible light photoredox catalysis. By condensing α-3° primary amines with electron-rich aryl aldehyde, we enable an oxidation and deprotonation event, which generates a key imidoyl radical intermediate. A subsequent β-scission event liberates alkyl radicals for coupling with electron-deficient olefins for the generation of unnatural γ-quaternary amino acids and other valuable synthetic targets.