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 clas s. A series of tri and tetrasubstituted olefins 2 were prepared and their b ehavior toward electrophiles was studied. The triisopropylsilyl groups coul d be readily removed by treatment with TBAF at 0 degreesC for 1 h or cesium acetate at 70 degreesC for 2 h. Soft and hard electrophiles were submitted to 2 under these conditions. The electrophiles can either react to yield d ouble 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. (C) 2001 El sevier Science Ltd. All rights reserved.