Li Yongli, Wang Huamin, Wang Zhuning, Alhumade Hesham, Huang Zhiliang, Lei Aiwen
College of Chemistry and Molecular Sciences, The Institute for Advanced Studies (IAS), Wuhan University Wuhan 430072 Hubei P. R. China
Chemical and Materials Engineering Department, Faculty of Engineering, King Abdulaziz University Jeddah 21589 Saudi Arabia.
Chem Sci. 2022 Dec 6;14(2):372-378. doi: 10.1039/d2sc05507d. eCollection 2023 Jan 4.
Selective C(sp)-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)-S bonds provided a powerful platform for the construction of target molecules. In contrast, the selective activation of widespread C(sp)-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)-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)-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.
选择性C(sp)-S键的断裂与转化在合成化学中仍然是一个特别重要但具有挑战性的目标。在过去几十年里，通过C(sp)-S键裂解的过渡金属催化交叉偶联反应为构建目标分子提供了一个强大的平台。相比之下，广泛存在的C(sp)-S键的选择性活化很少被研究，即使在相对苛刻的条件下也仍然发展不足。在此，公开了一种能够选择性活化C(sp)-S键的自由基介导的电化学策略，为从广泛存在的硫醚合成有价值的二硫化物提供了一种前所未有的方法。重要的是，与传统的过渡金属催化的C-S键断裂方法相比，该方法具有温和、无催化剂和无氧化剂的反应条件，以及对C(sp)-S键优异的化学选择性。初步机理研究表明，硫自由基物种参与反应途径并在控制位点选择性方面起重要作用。
