ABSTRACT
Among the different types of dendrimers, those incorporating phosphorus in various positions in their structure present undoubtedly the largest variety of constitutive elements of the core, branching units, internal branches, backbones, and surfaces due to the fascinating versatility of the organophosphorus chemistry. Main method of synthesis of phosphorus dendrimers consists in the repetition of two quantitative reactions, the first step being the nucleophilic substitution of Cl by hydroxybenzaldehyde in basic conditions. The second step is the condensation of the aldehydes with the dichlorophosphothiohydrazide. All the reactions are quantitative in most cases, using less than 5% excess of reagents. The replacement of hydroxybenzaldehyde also offers the possibility to multiply more rapidly the number of terminal functions, using phenol dialdehydes. The Staudinger reaction applied to thiophosphoryl azides has been extremely useful for the synthesis of dendrimers. Janus dendrimers are formed with two dendrimeric wedges linked by their core, and having different terminal functions.
