d domino hydrosilylation of substrates carrying unsaturated functionalities in a proximal arrangement is presented to produce silacycles. Excellent levels of efficiency and selectivity were achieved in the cyclization by the deliberate choice of the hydrosilane reagents. The key to successful cyclic hydrosilylation is the reactivity enhancement of the second intramolecular hydrosilylation by a proximity
Pd(OAc)<sub>2</sub>/P(<i><sup>c</sup></i>C<sub>6</sub>H<sub>11</sub>)<sub>3</sub>-Catalyzed Allylation of Aryl Halides with Homoallyl Alcohols via Retro-Allylation
fashion via a conformationally regulated six-membered cyclic transition state, the allylation reactions are highly regio- and stereospecific when homoallyl alcohols having a substituted allyl group are used. Whereas triarylphosphine is known to serve as a ligand for the palladium-catalyzed allyl transfer reactions, tricyclohexylphosphine proves to significantly expand the scopes of aryl halides to electron-rich
Gallium-mediated allyl transfer from bulky homoallyl alcohol to aldehydes or alkynes: Control of dynamic σ-allylgalliums based on retro-allylation reaction
reagent and gallium trichloride, bulky homoallylalcohols undergo gallium-mediated retro-allylation reaction to provide σ-allylgallium reagents. The σ-allylgallium reagents generated were applied to carbonyl allylation. The retro-allylation reaction generates (Z)- and (E)-σ-crotylgalliums stereospecifically, starting from erythro- and threo-homoallyl alcohols, respectively. The stereochemically defined
Preparation of 1,4-Dienes from 2-(2-Hydroxyalkylseleno)benzothiazoles by the Reaction Involving Se → O Azaaromatic Ring Rearrangement
作者:Koichi Shibata、Oyo Mitsunobu
DOI:10.1246/bcsj.65.3163
日期:1992.11
The reactions of 2-(2-oxoalkylseleno)benzothiazoles with allylic Grignard reagents in the presence of BF3·OEt2 gave the corresponding 2-[(2-alkyl-2-hydroxy-4-pententyl or 2-alkyl-2-hydroxy-4-methyl-4-pentenyl)seleno]benzothiazoles which, on treatment with Ph3P and NaH, afforded 1,4-dienes in good to excellent yields.
作者:Phil Ho Lee、Yunkiu Heo、Dong Seomoon、Sundae Kim、Kooyeon Lee
DOI:10.1039/b417975g
日期:——
The reactions of terminal alkynes with allylgallium reagents generated in situ from gallium and allyl bromides gave the corresponding 1,4-dienes in good yield via Markovnikov addition in THF at 70 °C.