Complex Bioactive Alkaloid‐Type Polycycles through Efficient Catalytic Asymmetric Multicomponent Aza‐Diels–Alder Reaction of Indoles with Oxetane as Directing Group

Starting from three achiral compounds, the title reaction provides rapid access to a variety of molecules that contain indoline, tetrahydroquinoline, and tetrahydroisoquinoline moieties (see scheme). The process features the efficient formation of multiple new bonds and chiral centers, excellent stereoselectivity, oxetane desymmetrization, and easy product purification through filtration.