Aminosulfenylations alkenes

Aminosulfenylation of alkenes can also be achieved by trapping the highly reactive (methylthio)-ammonium tetrafluoroborate, formed in situ by alkylation of /V, /V-dimethyImethanesulfenamide with trimethyloxonium tetrafluoroborate42. 

As for the base-promoted thioetheriiication, Shen and Wang reported in 2005 that highly electrophilic alkenes such as fluorinated vinylstannanes 172 could be converted to fluorinated vinyl sulfides 173 with ( )-selectivity via a nucleophilic addition of thiols to alkenes and defluorination 174 followed by destannylation (Scheme 46.22). In 2008, Cordova developed an organocatalytic enantioselec-tive aminosulfenylation of a,(3-unsaturated aldehydes 175 using A -(benzylthio)succinimides 176 in the presence of a TMS-protected chiral diarylprolinol. ° The reaction proceeded with low diastereoselectivities but with excellent enantioselectivities. The reason for the low diastereoselec-tivity might lie in the rapid epimerzation of Ca-H bond under the enamine catalysis 178. 

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