Photoredox-Mediated Remote C(sp3)-H Heteroarylation of N-Alkyl Sulfonamides.

A Minisci-type δ-selective C(sp3)-H heteroarylation of sulfonyl-protected primary aliphatic amines with N-heteroarenes under photore-dox-catalyzed conditions was developed. The reaction typically uses a slight excess of amine reactant. The use of benziodoxole acetate (BI-OAc) oxidant and hexafluoroisopropanol solvent is critical to achieve high yield. Besides methylene C-H bonds, heteroarylation reactions of δ methyl C-H bonds also worked under more forced conditions. The reactions show a broad scope for both amine and N-heteroarene substrates, offering a straightforward method for synthesis of complex δ-heteroarylalkylmines from simple precursors.