Oxidative dual C–H sulfenylation: A strategy for the synthesis of bis(imidazo[1,2-a]pyridin-3-yl)sulfanes under metal-free conditions using sulfur powder

Diethyl phosphite-mediated switchable synthesis of bis(imidazoheterocycles) derived disulfanes and sulfanes using imidazoheterocycles and octasulfur

“…These data are consistent with literature values. 13a Gram-scale reaction : Followed GP1 using 2-(p-tolyl)imidazo[1,2-a]pyridine 1b (1.05 g, 5.0 mmol, S 8 (1.60 mg, 50.0 mmol) and diethyl phosphite (345.0 mg, 322 μL, 2.5 mmol) DMSO (20 mL) for 24 h. Purification by flash column chromatography (silica gel, 40% EtOAc in pet ether) yielded title compound 2b (1.44 g, 60%) as a colorless solid.…”

“…12 Recently, substantial efforts have been devoted to the sulfur-bridged imidazo[1,2- a ]pyridines using a wide range of sulfur reagents through direct C–S–C bond formation (Scheme 1a). 13 However, these methods often involve transition-metal catalysts; usually, pre-functionalization of IP using iodine source and unavoidably excess use of odorous sulfur source are required. Compared with other sulfur surrogates, octasulfur (S 8 ) is air-stable, generally crystalline solid, easy to handle, odorless and utilized to synthesize various organosulfur compounds and heterocycles.…”

100% atom-economical and highly regio- and stereoselective iodosulfenylation of alkynes: a reagentless and sustainable approach to access (E)-β-iodoalkenyl sulfides and (Z)-tamoxifen

“…4,5 Moreover, alkenyl sulfides, an important class of organosulfides, are found in various biologically active molecules including natural products 6 and they are also utilized in materials science. 7 Although several synthetic strategies of sulfenylation reactions such as C–H sulfenylation and cross dehydrogenative coupling (CDC) have been developed for the synthesis of organosulfides, 8 very few are focused on accessing valuable β-haloalkenyl sulfides. For example, Nishihara et al reported an iron-induced radical anti-addition of sulfenyl chlorides to alkynes under ambient temperature to synthesize β-chloroalkenyl sulfides.…”

Visible light/copper catalysis enabled alkylation of silyl enol ethers with arylsulfonium salts

“…The aryl alkyl thioether motifs widely occur in pharmaceuticals, biological molecules, dyes, and natural products (Scheme 1). 1 In particular, aryl alkyl thioethers are very important synthetic intermediates in the synthesis of sulfones, sulfoxides, and other organosulfur compounds. 2 Therefore, much effort has been devoted to developing diverse synthetic methods for aryl alkyl thioethers.…”