One-pot access to pyridocoumarins via Povarov-hydrogen transfer cascade under auto-tandem catalysis of iodine in aqueous micelles

A cascade of inverse electron demand Diels–Alder reaction of 6-aminocoumarin-derived aldimines with an excess of styrene and oxidative aromatization of the formal Povarov adducts under autotandem iodine catalysis in aqueous micellar conditions provides direct access to a small library of substituted pyridine annulated coumarins in good to acceptable yields (12 examples). The unusual formation of linearly annulated pyridocoumarins under essentially neutral conditions is a remarkable feature of the protocol.