Gas-phase carbanion rearrangements. Does the Wittig rearrangement occur for deprotonated vinyl ethers?
作者:Peter C. H. Eichinger、John H. Bowie
DOI:10.1039/p29900001763
日期:——
Deprotonation of alkyl vinyl ethers (CH2CHOR) with NH2– in the gas phase yields the two carbanions CH2OR and –CHCHOR. The former ion can be synthesized specifically using the SN2(Si) reaction CH2C(SiMe3)OR + NH2–→CH2OR + Me3SiNH2: the ion undergoes several competitive and characteristic collision-induced reactions. For example, (i) when R Et, elimination of an alkene, i.e. CH2OR→(CH2CHO)–+(R–H), and
Enantioselective activation of ethers by chiral organoaluminum reagents: Application to asymmetric Claisen rearrangement
作者:Keiji Maruoka、Hiroshi Banno、Hisashi Yamamoto
DOI:10.1016/s0957-4166(00)86119-4
日期:1991.1
asymmetric Claisenrearrangement of allylvinylethers has been effected with a chiral organoaluminumreagent, (R)-1 or (S)-1 as an example of the enantioselective activation of ether substrates. This method provides a facile asymmetric synthesis of various acylsilanes and acylgermanes with high optical purity. Among various trialkylsilyl substituents of chiral organoaluminumreagent 1, use of the more
Generation of Radical Species from Cyclohexane-1,2-dione and the Reaction with Olefins: Preparation of 4,5-Dihydro-7(6<i>H</i>)-benzofuranone Derivatives
作者:Masanori Miura、Noriyoshi Arai、Koichi Narasaka
DOI:10.1246/bcsj.71.1437
日期:1998.6
Oxidation of cyclohexane-1,2-dione with ammoniumhexanitratocerate(IV) (CAN) generates 2,3-dioxocyclohexyl radical, which reacts with electron-rich olefins to afford the corresponding addition products. The adducts thus generated are converted to 4,5-dihydro-7(6H)-benzofuranone by acid treatment. In addition to cyclohexane-1,2-dione, radical species are also generated from cyclopentane-1,2-dione and
Cross-coupling of organosilanes with organic halides mediated by a palladium catalyst and tris(diethylamino)sulfonium difluorotrimethylsilicate
作者:Yasuo Hatanaka、Tamejiro Hiyama
DOI:10.1021/jo00239a056
日期:1988.2
A conjugate addition-elimination route to alkenoyltrimethylsilanes
作者:Robert F. Cunico、Cui-ping Zhang
DOI:10.1016/0040-4020(95)00561-l
日期:1995.1
Monosubstitution of 3,3-dichloro-1-(trimethylsilyl)2-propenone (1) with organocuprates stereoselectively affords E-3-alkyl- and Z-3-phenyl-3-chloro-1-(trimethylsilyl)-2-propenones. Further substitution proceeds stereoselectively as a function of extant and incoming substituents. 1 was also reduced to E-3-chloro-1-(trimethylsilyl)-2-propenone and the latter converted to E-3-alkyl- and E-3-phenyl-1-(trimethylsilyl)-2-propenones.