Fig. 2: Evaluation of reaction conditions.

Standard conditions: 2a (0.10 mmol), 1a (10 mol%), oxone (2.0 equiv.), TMDSO (4.0 equiv.), H₂O (1.1 equiv.) in 1.0 mL MeCN at r.t. for 18 h. Yields were determined by ¹H NMR analysis of the crude reaction mixture. TBHP   tert-butyl hydroperoxide, BPO   benzoyl peroxide.