Unveiling the Synthetic Potential of Substituted Phenols as Fully Recyclable Organophotoredox Catalysts for the Iodosulfonylation of Olefins
Cristian Rosso, Sara Cuadros, Giorgia Barison, Paolo Costa, Marina Kurbasic, Marcella Bonchio, Maurizio Prato, Luca Dell’Amico, Giacomo Filippini
Abstract
We describe an efficient photocatalytic procedure for the direct iodosulfonylation of terminal olefins 3 with α-iodo phenylsulfones 4. Specifically, the process uses the simple, robust, and fully recyclable phenol derivative 6e as the precatalytic system and occurs with visible-light irradiation (450 nm). Mechanistic investigations proved the key role of the in situ generated photocatalyst, namely phenolate anion 7e, which has shown high catalytic activity and considerable stability toward the operating conditions. Importantly, this photocatalytic transformation provides a wide variety of densely functionalized alkyl iodides 5 (23 examples, up to 95% yield). Finally, the synthetic potential of this photochemical transformation was demonstrated by scaling up the process under microfluidic conditions (up to 0.67 mmol h-1) while accessing a series of relevant product manipulations.