Electrochemical radical-mediated selective C(sp(3))–S bond activation

Selective C(sp(3))–S bond breaking and transformation remains a particularly important, yet challenging goal in synthetic chemistry. Over the past few decades, transition metal-catalyzed cross-coupling reactions through the cleavage of C(sp(3))–S bonds provided a powerful platform for the construction of target molecules. In contrast, the selective activation of widespread C(sp(3))–S bonds is rarely studied and remains underdeveloped, even under relatively harsh conditions. Herein, a radical-mediated electrochemical strategy capable of selectively activating C(sp(3))–S bonds is disclosed, offering an unprecedented method for the synthesis of valuable disulfides from widespread thioethers. Importantly, compared with conventional transition-metal catalyzed C–S bond breaking protocols, this method features mild, catalyst- and oxidant-free reaction conditions, as well excellent chemoselectivity towards C(sp(3))–S bonds. Preliminary mechanistic studies reveal that sulfur radical species are involved in the reaction pathway and play an essential role in controlling the site-selectivity.