Kuzmin Julius, Röckl Johannes, Schwarz Nils, Djossou Jonas, Ahumada Guillermo, Ahlquist Mårten, Lundberg Helena
Department of Chemistry, KTH Royal Institute of Technology, 10044, Stockholm, Sweden.
Angew Chem Int Ed Engl. 2023 Sep 25;62(39):e202304272. doi: 10.1002/anie.202304272. Epub 2023 Jul 21.
Thioethers are highly prevalent functional groups in organic compounds of natural and synthetic origin but remain remarkably underexplored as starting materials in desulfurative transformations. As such, new synthetic methods are highly desirable to unlock the potential of the compound class. In this vein, electrochemistry is an ideal tool to enable new reactivity and selectivity under mild conditions. Herein, we demonstrate the efficient use of aryl alkyl thioethers as alkyl radical precursors in electroreductive transformations, along with mechanistic details. The transformations proceed with complete selectivity for C(sp )-S bond cleavage, orthogonal to that of established transition metal-catalyzed two-electron routes. We showcase a hydrodesulfurization protocol with broad functional group tolerance, the first example of desulfurative C(sp )-C(sp ) bond formation in Giese-type cross-coupling and the first protocol for electrocarboxylation of synthetic relevance with thioethers as starting materials. Finally, the compound class is shown to outcompete their well-established sulfone analogues as alkyl radical precursors, demonstrating their synthetic potential for future desulfurative transformations in a one-electron manifold.
硫醚是天然和合成来源的有机化合物中高度普遍存在的官能团，但作为脱硫转化的起始原料仍未得到充分探索。因此，非常需要新的合成方法来挖掘这类化合物的潜力。在这方面，电化学是在温和条件下实现新的反应性和选择性的理想工具。在此，我们展示了芳基烷基硫醚作为电还原转化中烷基自由基前体的有效应用以及反应机理细节。这些转化对C(sp³)-S键断裂具有完全的选择性，与已确立的过渡金属催化的双电子途径正交。我们展示了一种具有广泛官能团耐受性的加氢脱硫方案，吉斯型交叉偶联中脱硫C(sp³)-C(sp³)键形成的首个实例，以及以硫醚为起始原料的具有合成意义的电羧化的首个方案。最后，这类化合物被证明作为烷基自由基前体优于其已确立的砜类似物，展示了它们在单电子体系中未来脱硫转化的合成潜力。
