One-Step Preparation of<i>α</i>-Chloro-<i>α</i>,<i>β</i>-unsaturated Carbonyl Compounds by the Reaction of Silyl Enol Ethers with TiCl<sub>4</sub>–LiAlH<sub>4</sub>–CCl<sub>4</sub>
作者:Michiharu Mitani、Yoshinori Kobayashi
DOI:10.1246/bcsj.67.284
日期:1994.1
Reaction of silylenolethers in a system composed of TiCl4, LiAlH4, and CCl4, which generates dichlorocarbene, produced α-chloro-α,β-unsaturated carbonylcompounds in an one-step process.
A Pd-catalyzed oxidative silylation of simple olefins with hexamethyldisilane to give allylsilanes has been achieved usingmolecularoxygen as the sole oxidant. The reaction provides a useful protocol to access synthetically useful allylsilanes from easily accessible simple olefins and hexamethyldisilane without using any oxidants other than O2.
A new reaction in organosilicon chemistry: the oxidative ring closure of allylsilanes with ceric ammonium nitrate
作者:Stephen R. Wilson、Corinne E. Augelli-Szafran
DOI:10.1016/s0040-4020(01)86650-3
日期:1988.1
Allylsilanes containing heteroatom nucleophiles yield cyclic products when treated with (NH4)2Ce(NO3)6. For example, hydroxy and amido-containing allylsilanes yield the corresponding tetrahydrofuran, tetrahydropyran, and piperidine analogs. These reactions and their application to natural product synthesis will be discussed.
Reactivity and regioselectivity in the reaction of allylsilanes and some analogous all-carbon alkenes with sulfur trioxide
作者:Hans Cerfontain、Johannes B. Kramer、Ruud M. Schonk、Bert H. Bakker
DOI:10.1002/recl.19951140907
日期:——
20 min in yields of > 95%. 1-(Trimethylsilyl)-2-cycloheptylideneethane (12a) at −60°C gives a mixture of the trimethylsilyl sulfonate ester 12c and the isomeric 1-(trimethylsilyl)-2-(1-cycloheptenyl)ethane-2-sulfonic acid (12f) in a molar ratio of 4:6. With 1-(trimethylsilyl)-2-(1,2,3,4-tetrahydro-1-naphthylidene)- ethane (18a) the exclusive product is 1-(trimethylsilyl)-2-(3,4-dihydro-1-naphthyl)ethane-2-sulfonic
Metalation of alk-1-enes, using the mixture of butyllithium and potassium tert-butoxide in tetrahydropyran, followed by stereohomogenization and ultimate treatment with chlorotrimethylsilane afforded a series of alk-2-enyltrimethylsilanes in good yield and with (Z/E) ratios ranging from 95:5 to 98:2. The deprotonation of propene can be rapidly and readily accomplished with a stoichiometric amount of the superbase suspended in pentane on a 1 mol scale.