Divergent Synthesis of Disulfanes and Benzenesulfonothioates Bearing 2‐Aminofurans From N‐Tosylhydrazone‐Bearing Thiocarbamates

Abstract

An efficient and convenient synthesis of valuable disulfanes and benzenesulfonothioates, having a 2-aminofuran framework, has been developed by employing a copper-catalyzed transformation of readily available N-tosylhydrazone-bearing thiocarbamates. This method features an inexpensive metal catalyst, mild reaction conditions, good functional-group tolerance, short reaction times, and delivers valuable and complex products. A copper carbene generated from an N-tosylhydrazone-bearing thiocarbamate is proposed as the key intermediate for the transformation and it triggers the subsequent cascade. Remarkably, the Ts anion released from N-tosylhydrazone further serves as a nucleophile, thus rendering the formation of benzenesulfonothioates under controlled conditions.

Biomimetic Carbene Cascades Enabled Imine Derivative Migration from Carbene-Bearing Thiocarbamates

“…However, the paucity of straightforward methods for the constructions of thiocarbamates and suitable functional groups in one molecule, which could ignite the intramolecular cascade reaction, makes it difficult to forge such types of transformations. Inspired by the Barton−Kellogg reaction, we reported an efficient Cucatalyzed synthesis of sulfur-containing 2-aminofurans in 2017 7 (Figure 1B). However, the transformation was not compatible with ketone-derived hydrazones; in other words, the substituent R in Figure 1B must be H, which heavily restricted the diversity and versatility of the products.…”

Disproportionate Coupling Reaction of Sodium Sulfinates Mediated by BF3·OEt2: An Approach to Symmetrical/Unsymmetrical Thiosulfonates

“…Organosulfur compounds have attracted considerable attention because of their interesting medicinal, material, and agrochemical applications in recent years . Among them, thiosulfonates are of particular interest, for they have shown a broad spectrum of pharmaceutical and clinical properties such as bactericidal, antimicrobial and fungicidal activities . In addition, thiosulfonates have been widely used as reagents or intermediates in laboratory and industrial organic chemistry due to many advantages, including much better reactivity and stability than commonly used sulfenyl halides and disulfides .…”

Copper in Efficient Synthesis of Aromatic Heterocycles with Single Heteroatom

“…A divergent synthesis of 2-aminofuran framework containing disulfanes and benzenesulfonothioates was developed by Song and co-workers using copper-catalyzed cascade transformation of readily available N-tosylhydrazone-bearing thiocarbamate (Scheme 46). [68] For the synthesis of benzenesulfonothioates (134) derivatives CuBr 2 (20 mol-%), DBU base (1.2 equiv.) and 1,4-dioxane solvent were used at 60°C heating condition and for disulfane (135) formation CuCl 2 (20 mol-%), DBU (2 equiv.)…”