Hydrophosphanation of Phenolic Aldehydes as Facile Synthetic Approach to Catechol‐Functionalized Phosphane Oxides and Phosphanes

Abstract Reactions of diphenylphosphane with mono‐ and dihydroxybenzaldehydes yield as initial products α‐phosphanyl‐carbinols that exist according to NMR studies in dynamic equilibrium with the starting materials in solution but are stable in the solid state. The facile rearrangement of the initial products yields isomeric phosphane oxides which react with MeI and excess LiAlH4 via deoxygenation to give the corresponding phosphanes. Phosphane oxides and phosphanes were isolated and characterized by analytical and spectroscopic data. The reactions described represent an improved synthesis for phosphanes with phenol and catechol functionalities that are useful for applications as ligands or supramolecular building blocks.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)