Alexandrine Maraval

Tailored Control and Optimisation of the Number of Phosphonic Acid Termini on Phosphorus‐Containing Dendrimers for the Ex‐Vivo Activation of Human Monocytes

The syntheses of a series of phosphonic acid-capped dendrimers is described. This collection is based on a unique set of dendritic structural parameters-cyclo(triphosphazene) core, benzylhydrazone branches and phosphonic acid surface-and was designed to study the influence of phosphonate (phosphonic acid) surface loading towards the activation of human monocytes ex vivo. Starting from the versatile hexachloro-cyclo(triphosphazene) N(3)P(3)Cl(6), six first-generation dendrimers were obtained, bearing one to six full branches, that lead to 4, 8, 12, 16, 20 and 24 phosphonate termini, respectively. The surface loading was also explored at the limit of dense packing by means of a first-generation dendrimer having a cyclo(tetraphosphazene) core and bearing 32 termini, and with a first-generation dendrimer based on a AB(2)/CD(5) growing pattern and bearing 60 termini. Human monocyte activation by these dendrimers confirms the requirement of the whole dendritic structure for bioactivity and identifies the dendrimer bearing four branches, thus 16 phosphonate termini, as the most bioactive.

Design of tailored multi-charged phosphorus surface-block dendrimers

Polycationic or neutral dendrons of generation 1 to 3 bearing protonated (or not) amino end groups and a vinyl group at the focal point as well as polyanionic or neutral dendrons of generation 1 to 3 decorated with carboxylate or carboxylic groups on their surface and exhibiting a vinyl group at the core were prepared. Addition of ethylenediamine to the vinyl core of dendrons having amino end groups allowed the synthesis of uniquely tailored water-soluble phosphorus bis-dendrons via core to core assembling of dendrons having a vinyl core. In preliminary experiments layer-by-layer deposition of bis-dendrons on silica surface was demonstrated.

Phosphorus Compounds as Cyclization Promoted Reagents: Preparation of 1,4-α3,γ3-Diphospha-2,6-Diazines

Abstract lmines are important classes of compounds in chemistry. In our continued investigation in the studies of the interactions betwcen group 4 (Zr, Ti) elements and main group elements we recently developped a new methodology for the preparation of various σ3, λ3 phospha-imines. Extension of this work allowed us to prepare unprecedented 8-π electron 6-membered phosphorus heterocycles; 1, 4 σ3, λ3 diphospha-2,6-diazines. The formation of these diazines involved for the first time the use of phosphorus derivatives as cyclization promoted reagents in zirconocene chemistry.