Enantioselective Synthesis of trans-Dihydrobenzofurans via Primary Amine-Thiourea Organocatalyzed Intramolecular Michael Addition
writer：Aidang Lu, Keling Hu, Youming Wang,* Haibin Song, Zhenghong Zhou,* Jianxin Fang, and Chuchi Tang
keywords：Enantioselective Synthesis, Thiourea, Michael Addition
source：期刊
specific source：Journal of Organic Chemistry
Issue time：2012年
A primary amine-thiourea organocatalyzed intramolecular Michael addition access was developed for the synthesis of trans-dihydrobenzofurans. Under the catalysis of an (R,R)-1,2 diphenylethylamine derived primary aminethiourea bearing a glucosyl scaffold, the corresponding transdihydrobenzofurans were obtained in high yields with excellent level of enantioselectivities (94 to >99% ee). Moreover, an in situ isomerization occurring at high temperature gave good to excellent trans/cis ratios as well (trans/cis: 84/16-96/4).