Carbolithiation and Cascade Reactions of o-Amino-(E)-Stilbenes

Significance

Protected o-amino-(E)-stilbenes, readily available, for instance, via cross-coupling reactions, can be carbolithiated by alkyllithium reagents and trapped by various electrophiles, usually affording diastereomeric mixtures of the products. The products can further undergo cyclization reactions. This method can be successfully applied to the preparation of relatively complex functionalized quinoline or dihydroquinoline derivatives via a cascade reaction sequence.