A method is described for carrying out indium-mediatedallylation reactions of phenacyl bromides in aqueous solution that form homoallylic bromohydrins. By employing subsequent base treatment, the homoallylic bromohydrins were converted to allylic epoxides. Finally, the process has been used as a key step in a concise sequence for the synthesis of 3-allylbenzofuran.
Simple Synthetic Method of Allyl- and Vinyl-Epoxides by Allylation of Carbonyl Groups with Allylic Tins Catalyzed by PbI<sub>2</sub>-HMPA
作者:Ikuya Shibata、Shoji Fukuoka、Akio Baba
DOI:10.1246/cl.1998.533
日期:1998.6
the chemoseletive allylation at the carbonyl groups of α-bromo ketones with allylic tin, where PbI2-HMPA effected as a chemoselective catalyst. Moreover, vinyl epoxides were obtained in one pot procedure by the PbI2-HMPA catalyzed reaction of γ-chloroallyltri-n-butyltin with aldehydes. Because of the mildness of the catalyst, the formed epoxide functionalities were not decomposed.
An efficient synthetic method for allyl-epoxides via allylation of α-haloketones or esters with allylmagnesium bromide
作者:Liyuan Fan、Min Zhang、Songlin Zhang
DOI:10.1039/c2ob00051b
日期:——
A simple, efficient, and non-metal-catalyzed synthetic method for allyl-epoxides and diallyl-epoxides by allylation of α-haloketones and esters with allylmagnesium bromide in mild conditions is reported in this article. It inherited some advantages of the organomagnesium reagents such as availability, operational simplicity and low toxicity.
The cyclization reaction of diallyldibutyltin and α- or γ-halo ketones, especially chloro-substituted ketones, effectively proceeds in the presence of a catalytic amount of tetraethylammonium chloride, producing the corresponding 2-allyloxiranes or 2-allyltetrahydrofurans in high yield, respectively. β-Chloro ketones give the corresponding allyl alcohols.
Multi-Product Classes Obtained from Allylation of α-Halo Ketones with Allylzinc Bromide
作者:Min Zhang、Yuanyuan Hu、Songlin Zhang
DOI:10.1002/chem.200901487
日期:2009.10.19
An efficient, one‐pot synthesis procedure for the preparation of allylic epoxides, aldehydes and homoallylic alcohols (see scheme) has been described. The three industrial products were synthesized by the reaction of allylzinc bromide with α‐halo ketones under non‐catalytic conditions with p‐toluenesulfonic acid and ytterbium triflate as catalysts, respectively. Feasible reaction mechanisms and intermediates