Enantioselective Synthesis of <i>trans</i>-Dihydrobenzofurans via Primary Amine-Thiourea Organocatalyzed Intramolecular Michael Addition

A primary amine-thiourea organocatalyzed intramolecular Michael addition access was developed for the synthesis of <i>trans</i>-dihydrobenzofurans. Under the catalysis of an (<i>R</i>,<i>R</i>)-1,2-diphenylethylamine derived primary amine-thiourea bearing a glucosyl scaffold, the corresponding <i>trans</i>-dihydrobenzofurans 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 <i>trans</i>/<i>cis</i> ratios as well (<i>trans</i>/<i>cis</i>: 84/16–96/4)