Synthesis of hybrid dendritic molecules with diazaphospholidine oxide grafted at the surface of octavinylsilsesquioxane (OVS)

A range of dendritic molecules was made using the monodentate SEMI-ESPHOS phosphine oxide ligand, which was derivatised with a series of functional groups including bromide, vinyl, allyl and terminal alkyne. Several methods to attach the resulting precursors onto octavinylsilsesquioxane (OVS), ranging from hydrosilylation, Suzuki, Heck, Grubbs or Sonogashira coupling reactions, have been investigated. Cross-metathesis of SEMI-ESPHOS oxide dendrons containing vinyl end groups with OVS catalyzed by Grubbs' catalyst was proven to be effective in the formation of precursors for dendritic molecules based on OVS.