Mesoporous polyphosphamide catalyzed heterogeneous one-pot Wittig olefination

Abstract

Phosphamides comprising –{P^V(O)NH}– linkages are used as ligand scaffolds to prepare pharmaceutical products, whereas their polymeric forms are employed as flame retardants. A mesoporous triazole-functionalized polyphosphamide (t-PPA) is reported herein as a heterogeneous organocatalyst for the catalytic Wittig reaction, achieving a cumulative TON of 1176 upon recycling. In situ reduction of the –{P^V(O)}– unit in t-PPA leads to one-pot catalytic olefination with a wide substrate scope and preferential E-configuration. Unlike the sensitive phosphine-based catalysts reported earlier for olefination, polyphosphamides can be used as robust analogs with a versatile scope for exploring P^V/III-mediated catalysis.