Stereoselective cyclomagnesiation of 1,6-heptadienes catalyzed by zirconocenes: Effects of substituents, solvent and magnesium reagents
摘要:
Zirconocene dichloride acts as a catalyst precursor for the stereoselective cyclomagnesiation of an array of substituted 1,6-heptadienes in the presence of butylmagnesium chloride to form trans 1,2-(bis)methylmagnesium substituted carbocycles.
The Regiochemistry of Carbenoid Insertion into Zirconacycles
作者:George J. Gordon、Tim Luker、Mark W. Tuckett、Richard J. Whitby
DOI:10.1016/s0040-4020(99)01094-7
日期:2000.4
lithium chloroallylides (allyl carbenoids) into a wide variety of unsymmetrical zirconacycles has been determined. In all but one case a single regioisomer was obtained. A combination of steric and electronic effects is needed to explain the results and imply that the carbenoid is acting predominantly as an electrophilic species. The first carbenoid insertion into a zirconacyclopentadiene is noted.