Dimethyl(methylthio)sulfonium Tetrafluoroborate (DMTSF)

Regio- and Stereoselective Synthesis of β-Methylthio Vinyl Triflates

“…Their most outstanding utility across organic synthesis was established decades ago as the sulfenofunctionalization of alkenes. 12,13 In this old context, studies have focused on exploring the scope of the nucleophiles. As a consequence, important findings have facilitated various powerful methodologies for the synthesis of β-functionalized thioethers on the basis of the concept of electrophilic activation and subsequent nucleophilic addition of a carbon−carbon double bond.…”

“…The putative episulfonium ion intermediate determines that the process proceeds in a regio-and stereoselective manner. 49,50 An initial test to activate alkyne 1a with DMTSF, which was generally used in the pioneering works by Trost and Caserio, 12 led to the recovery of most of the alkyne starting material. However, when equal amounts of terminal alkyne 1a and DMTSM were mixed in dichloroethane (DCE) at ambient temperature (23 °C), the anticipated vinyl triflate product 2a was isolated in a promising yield of 45% (Table 1, entry 1).…”

Carbosulfenylation of Alkenes with Organozinc Reagents and Dimethyl(methylthio)sulfonium Trifluoromethanesulfonate

“…By submitting to the reported heteronucleophiles, intermediate thiosulfonium ion II can be persuaded to the conversion of its episulfonium analogue I prior to the formation of carbon-hetero bonds. Whereas, a typical nucleophilic carbon reagent with stronger basicity could result in fast decomposition of sulfonium salt II , thus excises anticipated carbon–carbon bond formation . As a consequence, most of the typical carbon nucleophiles have proved problematic to undergo the carbosulfenylation of alkenes initiated by DMTSF or DMTSM.…”

Synthesis of Enhanced, Isolable Disulfanium Salts and their Application to Thiiranium-Promoted Polyene Cyclizations

“…6 We also discovered that these reagents often performed better than other commercially available electrophilic alkyl sulfide reagents such as dimethyl(methylthio)sulfonium tetrafluoroborate (DMTSF). 7 Just a short while ago, the Denmark group, in a landmark discovery contemporaneous with these efforts, reported the first cases of effective asymmetric polyene cyclizations initiated by thiiranium ions. 8 Their process used an appropriate chiral Lewis base with a distinct aryl sulfide electrophile in 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) to convert electron-rich substrates such as 5 into 8 in good yield and with high levels of enantioselectivity.…”

“…7.06 (dd, J = 7.5, 1.7 Hz, 1 H), 3.95 (dd, J = 12.8, 4.1 Hz, 1 H), 3.03-2.86 (m, 2 H), 2.40 (dt, J = 13.1, 3.5 Hz, 1 H), 2.32 (dq, J = 13.9, 3.8 Hz, 1 H), 2.15 (qd, J = 13.5, 3.4 Hz, 1 H), 1.97 (ddt, J = 13.3, 7.1, 2.…”