无金属参与的氧原子邻位C(sp3)—S键的构筑

以二叔丁基过氧化物(DTBP)为氧化剂, 苯硫酚为硫化试剂, 在无金属参与的条件下, 于120 ℃下采用一步法合成了硫代苄醚. 这种构筑C(sp³)—S键的方法具有高原子经济性和高选择性的优点, 并以较高的收率获得了一系列目标化合物.

Metal-free Thiolation of C(sp3)—S Bond Adjacent to an Oxygen Atom†

The formation of C—S bonds is one of the most important transformations in organic chemistry due to the high prevalence of sulfur-containing molecules of biological and pharmaceutical relevance. Cross-dehydrogenative coupling(CDC) is more atom economical and environmentally friendly than traditional cross-coupling reactions. A facile and transition metal-free methodology for construction of C(sp³)—S bond was herein reported. With ditertbutyl peroxide(DTBP) as oxidant and thiophenol as thioetherification regent under 120 ℃, the high atom-efficiency and selective system offered the thiobenzylethers as products in acceptable to good yields. These new compounds were characterized via infrared(IR), nuclear magnetic resonance(NMR), and mass spectrometry(MS). The possible mechanism for the reaction was suggested as followed: benzyl ethers was oxidized by DTBP to generate intermediates A, which further reacted with thiophenol to form desired products. This direct thiolation method is a new protocol for the construction of C—S bonds, which might be very valuable and attractive in sulfur chemistry and radical chemistry.