Ln(III)/Chiral Brønsted Acid Catalyzed Asymmetric Cascade Ring Opening/Aza-Piancatelli Rearrangement of D–A Cyclopropanes

The first Lewis acid and chiral Brønsted acid cooperatively catalyzed asymmetric cascade ring opening/aza-Piancatelli rearrangement reaction of furyl-substituted donor–acceptor cyclopropanes is achieved, enabling the construction of functionalized aminocyclopentenones bearing α-quaternary carbon stereocenters in high yields with excellent enantio- and diastereoselectivities under remarkably low catalyst loading of 0.2–1.2 mol %.本研究首次实现了路易斯酸（Lewis acid）与手性布朗斯特酸（chiral Brønsted acid）协同催化的、以呋喃取代供体-受体环丙烷为底物的不对称级联开环/氮杂-Piancatelli重排反应。该反应可在催化剂负载量仅为0.2–1.2 mol%的条件下，以高收率及优异的对映选择性和非对映选择性，构建得到带有α-季碳立体中心的官能化氨基环戊烯酮类化合物。