Chiral Phosphoric Acid Catalyzed [3 + 2] Cycloaddition and Tandem Oxidative [3 + 2] Cycloaddition: Asymmetric Synthesis of Substituted 3-Aminodihydrobenzofurans
作者:Coralie Gelis、Mathieu Bekkaye、Clément Lebée、Florent Blanchard、Géraldine Masson
DOI:10.1021/acs.orglett.6b01593
日期:2016.7.15
Asymmetric [3 + 2] cycloaddition of quinones with ene- and thioene-carbamates was achieved by chiral phosphoric acid catalysis, providing the corresponding 3-amino-2,3-dihydrobenzofurans in excellent yields with moderate to good diastereoselectivities and excellent enantioselectivities. An asymmetric tandem oxidative cycloaddition protocol starting from hydroquinones was also accomplished with phenyliodine(III)
通过手性磷酸催化可实现醌与烯属和硫代氨基甲酸酯的不对称[3 + 2]环加成反应,从而以优异的产率提供相应的3-氨基-2,3-二氢苯并呋喃,并具有中等至良好的非对映选择性和出色的对映选择性。从对苯二酚开始的不对称串联氧化环加成方案也可以在同一反应容器中用二乙酸苯基碘(III)和手性磷酸完成。