Preparation and reactivity studies of 1,2-bis-triisopropylsilanylsulfanyl-alkenes

The cross-coupling reaction of bis-triisopropylsilyl disulfide 1 on alkynes yielded 1,2-bis-triisopropylsilanylsulfanyl-alkenes 2, a new chemical class. A series of tri and tetrasubstituted olefins 2 were prepared and their behavior toward electrophiles was studied. The triisopropylsilyl groups could be readily removed by treatment with TBAF at 0°C for 1 h or cesium acetate at 70°C for 2 h. Soft and hard electrophiles were submitted to 2 under these conditions. The electrophiles can either react to yield double-addition products with alkyl and activated halides, epoxides and acyl chlorides or cyclic adducts with chloroformate derivatives. In the latter case, 1,3-dithiol-2-ones or 1,3-dithiol-2-thiones are prepared.