Bicyclo[1.1.1]pentane (BCP) replacement as a bioisostere in drug molecules has an influence on their permeability, aqueous solubility and in vitro metabolic stability. Thus, the chemical installation of the BCP unit into a chemical entity remains a significant challenge from a synthetic point of view. Here, we have presented a new approach for the installation of the BCP unit on the xanthate moiety
A simple and efficient method to obtain α-xanthylmethyl ketones from α-diazo ketones is described. The reaction proceeds through a protonation/nucleophilic substitution sequence in the presence of p-toluenesulfonic acid and potassium ethyl xanthogenate as the nucleophile. As α-diazo ketones can be readily synthesized from ubiquitous carboxylic acids, a broad variety of xanthates can be obtained, including
Novel Route to Triethylsilyl-Substituted Cyclopropanes
作者:Shi-Guang Li、Samir Z. Zard
DOI:10.1021/ol503081b
日期:2014.12.5
Radical adducts of S-α-ketonyl dithiocarbonates (xanthates) to triethyl vinylsilane are converted into triethylsilyl-substituted cyclopropanes upon ozonolysis followed by exposure to 1,4-dibromobutane and Cs2CO3/18-crown-6 in refluxing acetonitrile. The sequence works best with phenacyl type adducts, and the use of the less bulky trimethysilyl (TMS) derivatives results in extensive desilylation.
S -α-酮基二硫代碳酸酯(黄原酸酯)与三乙基乙烯基硅烷的自由基加合物在臭氧分解后转化为三乙基甲硅烷基取代的环丙烷,然后在回流的乙腈中暴露于1,4-二溴丁烷和Cs 2 CO 3 / 18-crown-6。该序列最适用于苯甲酰基型加合物,使用体积较小的三甲基甲硅烷基(TMS)衍生物会导致大量的甲硅烷基化。
Ion radicals. XXXV. Reactions of thianthrene and phenoxathiin cation radicals with ketones. Formation and reactions of .beta.-ketosulfonium perchlorates and ylides
作者:Kyongtae Kim、Serugudi R. Mani、Henry J. Shine
DOI:10.1021/jo00914a008
日期:1975.12
A metal-free synthesis of oxindoles by a radical addition-cyclization onto N-arylacrylamides with xanthates
作者:Shucheng Wang、Xuhu Huang、Bowen Li、Zemei Ge、Xin Wang、Runtao Li
DOI:10.1016/j.tet.2015.01.049
日期:2015.3
A convenient, high yielding synthesis of oxindoles by metal-free di-functionalization of alkenes with xanthates has been developed. This transformation involves a radical addition/cyclization process. Various arylalkylation products including alkyl ester-, benzyl-, cyano-, ketone-, amine-, and amide-substituted oxindoles were prepared in good to excellent yields. (C) 2015 Elsevier Ltd. All rights reserved.