Fig. 2: Substrate scope of the aza-Paternò-Büchi reactions with H–Hexo selectivity.

Reaction conditions: 1 (0.2 mmol), 2 (0.1 mmol), and thioxanthone (0.01 mmol) in MeCN (2 mL) under irradiation with purple LEDs (λmax = 405 nm) at room temperature under nitrogen for 24 h. Boc tert-butoxycarbonyl, Ac acetyl, TBS tert-butyl(dimethyl)silyl, Ts tosyl.