Allylation of Aldehydes and Imines: Promoted by Reuseable Polymer-Supported Sulfonamide of <i>N</i>-Glycine
作者:Gui-long Li、Gang Zhao
DOI:10.1021/ol0528235
日期:2006.2.1
[reaction: see text] A allylation of aldehydes and imines (generated in situ from aldehydes and amines) with allyltributyltin promoted by recoverable and reusable the polymer-supportedsulfonamide of N-glycine has been developed. Good to high yields were obtained in various cases. Most of the SnBu(3) residue can be recovered as Bu(3)SnCl. Highly stereoselective synthesis of N-Boc-(2S,3S)-3-hydroxy-2-phenylpiperidine
Efficient Allylation of Aldehydes Promoted by Carboxylic Acids
作者:Gui-long Li、Gang Zhao
DOI:10.1021/jo050186q
日期:2005.5.1
mediating the allylation of aldehydes with allytributyltin in different solvents. A novel, general, and practical method of allylation of aldehydes promoted by carboxylic acids under mild reaction conditions has been developed. Among them, p-nitrobenzoic acid afforded high to quantitative yields of the homoallylicalcohol products, and can be easily recovered after workup by aqueous HCl. Glyoxylic
已经筛选出各种羧酸以在不同溶剂中介导醛与烯丙基三丁基锡的烯丙基化。已经开发了在温和的反应条件下烯丙基化由羧酸促进的醛的新颖,通用和实用的方法。其中,对硝基苯甲酸提供了高至定量产率的均烯丙基醇产物,并且在用HCl水溶液处理后可以容易地回收。乙醛酸自催化烯丙基化,而无需添加任何其他助催化剂或催化剂,从而以高收率得到相应的烯丙基化产物。通过控制羧酸的酸度,可以调节醛的丁酰化的区域选择性。醛的crotylation生产的α-加合物作为主要产物,使用CF可以中等至良好的收率3 CO 2 H作为促进剂。还讨论了烯丙基化的可能机制。
SnCl 2 /PdCl 2 -mediated aldehyde allylation in fully aqueous media
Catalyzed by PdCl2, SnCl2 can efficiently mediate the allylation of various aldehydes with allyl chloride or bromide, but not with allyl alcohol, in fully aqueous media. The yield of the reaction is very high (90–100%), and the reaction is operationally simple, environmental benign and easy to scale up.
Iron-mediated allylation of aryl aldehydes in aqueous media
作者:Tak Chung Chan、Chak Po Lau、Tak Hang Chan
DOI:10.1016/j.tetlet.2004.03.163
日期:2004.5
Iron metal was found to be able to mediate the allylationreaction of arylaldehydes in aqueousmedia with sodium fluoride as the promoter. The possible implication of an allyliron intermediate was examined.