One-Pot Regioselective Synthesis of Spiroimidazolidinones via a Sequential Ugi 4CR/Azide-Isocyanide Coupling/Cyclization/Rearrangement/Hydroxylation Reaction

Herein a novel and robust methodology to spiroimidazolidinones has been developed under a mild reaction. The reaction of (Z)-2-azido-3-phenylacrylic acids 1, aldehydes 2, amines 3, isocyanides 4, and isocyanides 6 produced regioselectively spiroimidazolidinones in 71–88% yields via a sequential Ugi 4CR/Pd(0) catalyzed azide-isocyanide coupling/cyclization/rearrangement/hydroxylation reaction. Furthermore, the easily accessible starting materials, high bond-forming efficiency, and broad substituent tolerance make this strategy useful in synthetic and medicinal chemistry.