gem-Difluoroenals are excellent substrates for asymmetricorganocatalytic 1,4-additions of thiols and anilines. By using diarylsilylprolinol ether as a catalyst, good to excellent yields with ee values in the same range (up to 98 %) were obtained. The CF2R group strongly activates the enals towards these organocatalytic additions.
gem-Difluoroenals 是硫醇和苯胺的不对称有机催化 1,4-加成的极好底物。通过使用二芳基甲硅烷基脯氨醇醚作为催化剂,在相同范围内的 ee 值(高达 98%)下获得了良好到极好的收率。CF2R 基团对这些有机催化添加物强烈激活烯醛。
Irreversible<i>endo</i>-Selective Diels-Alder Reactions of Substituted Alkoxyfurans: A General Synthesis of<i>endo</i>-Cantharimides
作者:Robert W. Foster、Laure Benhamou、Michael J. Porter、Dejan-Krešimir Bučar、Helen C. Hailes、Christopher J. Tame、Tom D. Sheppard
DOI:10.1002/chem.201406286
日期:2015.4.13
The [4+2] cycloaddition of 3‐alkoxyfurans with N‐substituted maleimides provides the first general route for preparing endo‐cantharimides. Unlike the corresponding reaction with 3H furans, the reaction can tolerate a broad range of 2‐substitued furans including alkyl, aromatic, and heteroaromatic groups. The cycloaddition products were converted into a range of cantharimide products with promising