Nucleophilic addition-elimination reactions of N-(p-tolylsulphonyl)vinylsulphoximines: preparation of α-methylene nitriles and phosphonates
作者:Peter L. Bailey、Richard F.W. Jackson
DOI:10.1016/0040-4039(91)80705-b
日期:1991.6
Treatment of N-(p-tolylsulphonyl)vinylsulphoximines (1) with lithium cyanide in DMF at room temperature leads to efficient formation of α,β-unsaturated nitriles (3), via a Michael addition-proton transfer-elimination process, in which the polarity of the double bond is reversed. Analogous reaction with lithium dimethylphosphonate leads to β-dimethylphosphonyl sulphoximines (7), which are converted
From vinyl sulfides, sulfoxides and sulfones to vinyl zirconocene derivatives
作者:Shahera Farhat、Irena Zouev、Ilan Marek
DOI:10.1016/j.tet.2003.08.074
日期:2004.2
An easy and straightforward new method for the preparation of sp2 zirconocene derivatives from a wide range of heterosubstituted alkenes such as vinyl sulfides, sulfoxides and sulfones is described. In all cases, a complete isomerization of the stereochemistry is observed and only the E-isomer is obtained. The reactivity of the resulting vinylic organometallic can be increased by a transmetalation
Preparation and Reaction of Phenylsulfonyl-substituted Dizinciomethane
作者:Yoko Baba、Akio Toshimitsu、Seijiro Matsubara
DOI:10.1246/cl.2007.864
日期:2007.7.5
Treatment of dibromomethyl phenyl sulfone with zinc powder in the presence of a catalytic amount of lead in THF afforded phenylsulfonyl-substituted dizinciomethane. The species converts a ketone or aldehyde into an alkenyl sulfone via a Wittig-type olefination reaction with the assistance of β-TiCl3.
A new desulphonylation of α,β-unsaturated sulphones via conjugate addition of tributylstannyl-lithium
作者:Masahito Ochiai、Tatsuzo Ukita、Eiichi Fujita
DOI:10.1039/c39830000619
日期:——
α,β-Unsaturatedsulphones (1) on treatment with tributylstannyl-Lithium in tetrahydrofuran at –78 °C, give the Michael type addition products, β-tributylstannyl sulphones (2), and their successive β-elimination by reaction with silica gel affords the desulphonylated olefins (3) in good yields.