Octakis(3-azidopropyl)octasilsesquioxane: A Versatile Nanobuilding Block for the Efficient Preparation of Highly Functionalized Cube-Octameric Polyhedral Oligosilsesquioxane Frameworks Through Click Assembly

9 páginas, 1 figura, 1 esquema, 2 tablasA one-step synthesis of octakis(3-azidopropyl)octasilsesquioxane from commercially available octakis(3-aminopropyl)octasilsesquioxane has been developed through a highly efficient diazo-transfer reaction under very mild conditions. Nonaflyl azide is shown to be a safer, cheaper, and more efficient reagent for this transformation than the better known and generally used diazo-transfer reagent triflyl azide. Octakis(3-azidopropyl)octasilsesquioxane is an excellent nanobuilding block that can be readily octafunctionalized with a range of terminal alkynes by copper(I)-catalyzed 1,3-dipolar azide–alkyne cycloaddition to provide new functional nanocages, maintaining a perfect 3D cubic symmetry. The mildness, simplicity, and efficiency of this approach have been demonstrated in the preparation of a glyco-polyhedral oligosilsesquioxane (POSS) conjugate and a BODIPY–POSS cluster (BODIPY=boron dipyrromethene).We thank the Ministry of Education and Science of Spain for financial support (projects CTQ-2006–15515-C02–02/BQU and MAT-2007-65778- C02-01) and for a FPU predoctoral fellowship to B.T.Peer reviewe