Sulfur-Mediated Electrophilic Cyclization of Aryl-Substituted Internal Alkynes

Abstract

A sulfur-mediated electrophilic cyclization reaction of aryl-tethered internal alkynes has been developed. Triflic anhydride-activated sulfoxides induced the electrophilic cyclization and then demethylation with triethylamine in one pot, affording 3-sulfenyl-1,2-dihydronaphthalenes and related types of products in yields of ≤96%.

Metal‐Free Synthesis of Selenodihydronaphthalenes by Selenoxide‐Mediated Electrophilic Cyclization of Alkynes

“…Apart from these substrates above, various 4-aryl-1-phenyl-1-butynes were examined in the reaction (Scheme 3). Different substituent at the para and ortho position were well tolerated with good yields, especially in the cases of halo (21,22,27) and cyano (24). Again, 1-naphthyl has no deleterious effect on the target reaction, leading to the corresponding product 28 in 84 % yield.…”

“…Herein, we describe the substrate scope of our investigation of such metal-free selenium-involved electrophilic cyclization, which provides selenium containing products with better derivatization reactivities than the corresponding sulfur counterparts. [21]…”

Synthesis of α-heterosubstituted ketones through sulfur mediated difunctionalization of internal alkynes

“…In connection with our recent interest in sulfur mediated C–H functionalization of alkenes16 and alkynes,17 we are interested in the reactivity of sulfonium vinyl triflate intermediate A generated through alkyne attack of triflic anhydride activated diphenyl sulfoxide (see Scheme 1e). 17a,18 We reasoned that if hydrolysis of A could give α-sulfonium ketone B , subsequent substitution with various nucleophiles in one pot would then afford different types of α-heterosubstituted ketones in a rapid and unified fashion.…”

Enantioselective Construction of Axially Chiral Amino Sulfide Vinyl Arenes by Chiral Sulfide‐Catalyzed Electrophilic Carbothiolation of Alkynes

“…Catalytic electrophilic thiolation reactions provide a facile and straightforward route for the transformation of alkenes and alkynes into sulfur-containing molecules. [18][19][20][21][22][23] In the past few years, considerable efforts have been devoted to the development of catalytic enantioselective versions of this reaction. Particularly, by chiral chalcogenophosphoramide [19,21] and chiral bifunctional chalcogenide catalysis, [22] a range of chiral sulfur-containing compounds could be prepared efficiently.…”