Enantioselective\nCascade Catalysis for the Construction\nof Tetrahydroquinolines

Secondary amines are widely used as robust catalysts\nfor the enantioselective\nfunctionalization of aldehydes, yet they are rarely employed as Lewis\nbases or hydrogen-bonding catalysts for alkene activation. In this\nstudy, we present a decarboxylative [4 + 2] cycloaddition of vinyl\nbenzoxazinanones with nitroolefins to construct tetrahydroquinolines\nthrough cascade catalysis. A single chiral morpholine catalyst sequentially\nfunctions as both a Lewis base and a hydrogen-bonding catalyst. These\nactivation modes effectively drive the cascade process and control\nthe stereochemistry.