Reaction of 3-zircona-1-cyclopentenes and zirconacyclopentanes with aldehydes. A selective and convenient synthesis of 4-penten-1-ols, (Z)-5-iodo-4-penten-1-ols, and related alkanols
3-Zircona-1-cyclopentenes and zirconacyclopentanes react with aldehydes at or below 25 °C to give the corresponding carbonyl addition products, i.e., 7-membered oxazirconacycles, which can be readily converted to the corresponding alcohols via protonolysis and 5-iodoalcohols via iodinolysis; the latter product can be further converted to 7-membered lactones via Pd-catalyzed carbonylation.
Studies on the zirconium-mediated alkyne–aldehyde coupling reactions: a facile synthesis of stereodefined allylic alcohols and (Z)-2-en-4-yn-1-ols
作者:Shenghai Guo、Hao Zhang、Feijie Song、Yuanhong Liu
DOI:10.1016/j.tet.2006.12.051
日期:2007.2
An improved zirconium-mediated alkyne–aldehyde cross-coupling reaction has been achieved to afford the stereodefined (Z)-allylic alcohols or 3-iodinated allylicalcoholsselectively via protonolysis or iodinolysis of the corresponding five-membered oxazirconacycles. This method has also been successfully applied to the synthesis of (Z)-enynols through cross-coupling reactions of three different components
One-pot four-component synthesis of tetrahydrofuran derivatives involving an alkyne, an ethylene and two aldehydes via CuCl-mediated reactions of oxazirconacyclopentenes with aldehydes
作者:Changjia Zhao、Jiang Lu、Jun Yan、Zhenfeng Xi
DOI:10.1016/s0040-4039(03)01741-6
日期:2003.9
In the presence of 1 equiv. of CuCl, the reaction of zirconacyclopentenes with 2 equiv. of aldehydes from −78°C to room temperature afforded tetrahydrofuran derivatives in good isolated yields upon hydrolysis with aqueous 3N HCl; oxazirconacycloheptenes, generated in situ from zirconacyclopentenes with one aldehyde, was found to be the reactive intermediate.