Photochemically-induced C–C bond formation between tertiary amines and nitrones†
Abstract
Photoexcited nitrones serve as excellent electron acceptors as well as radical acceptors in the presence of tertiary amines to give β-amino hydroxylamines via photochemically-induced direct sp3 C–H functionalization of the tertiary amines. The combined use of an organophotosensitizer and photoirradiation was highly effective in accelerating addition reactions. Several nitrones and tertiary amines were successfully utilized to give β-amino hydroxylamines in good yield. Highly regioselective generation of primary α-aminoalkyl radicals based on Lewis's stereoelectronic rule and diastereoselective addition reactions of primary α-aminoalkyl radicals with nitrones were successfully achieved. Furthermore, a highly diastereoselective reaction of an α-aminoalkyl radical with a chiral (E)-geometry-fixed α-alkoxycarbonylnitrone was performed.