Creating diversity: Multicomponentreactions for the synthesis of complexpiperidinescaffolds lead to high levels of skeletal, functional, and stereochemical diversity in an efficient way (see scheme, X=OR, NR2). Connecting the acid chloride component to the dienophile generates polycyclic piperidinescaffolds by an intramolecular Diels–Alder reaction of the in situ generated azadienes.