One-pot and highly regio-selective 1,3-dipole cycloaddition of azomethine ylide generated in situ to tetraethyl vinylidenebisphosphonate (VBP) catalyzed by cerium(iv) oxide

Abstract

VBP reacts smoothly with L-proline and benzaldehyde derivatives at 80 °C in toluene catalyzed by cerium(IV) oxide (CeO₂) to give the corresponding heterocyclic bisphosphonates in moderate yields (30–70%). A high regio-selectivity of the 1,3-dipole cycloaddition was observed. The structures of the targeted molecules are characterized by NMR (such as COSY, HSQC, and HMBC), IR and MS.