Preparation and reactivity studies of 1,2-bis-triisopropylsilanylsulfanyl-alkenes
摘要:
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 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 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. (C) 2001 Elsevier Science Ltd. All rights reserved.
Free Radical Reaction of Diisopropyl Xanthogen Disulfide with Unsaturated Systems
作者:Yves Gareau、André Beauchemin
DOI:10.3987/com-98-8230
日期:——
1,3-Dithiol-2-ones are prepared in one pot reaction from commercially available diisopropyl xanthogen disulfide (2) and alkynes under radical conditions. The 5-membered heterocycle is formed via a ring closure of vinyl radical (7) resulting from the thio radical addition of 5 to an alkyne. The reaction worked best for alkynes conjugated with a C=C double bond. The oxygen atoms of reagent (2) could be replaced by sulfur and this new reagent furnished 1,3-dithiol-2-thiones under radical conditions.
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 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 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. (C) 2001 Elsevier Science Ltd. All rights reserved.
JACOBSEN N.; MAYO P. DE; WEEDON A. C., NOUV. J. CHIM., 1978, 2, NO 4, 331-342