Polyester Dendrimers

Abstract

Polyester dendrimers have been comprehensively reviewed starting from their first synthesis in the early 1990s by Hawker and Fréchet. Polyester dendrimers have attracted and continue to attract extensive interest because they are comparatively easy to make and because, whenever they have been tested, they have been found to be non-toxic. A number of different strategies for their synthesis have been examined and the methods employed for formation of the ester bond during dendrimer assembly have been summarized. The newest approaches, including the use of bifunctional orthogonally reacting dendrons and accelerated synthesis have been surveyed.

Synthesis of biorenewable and water-degradable polylactam esters from itaconic acid

“…1 However, the overutilization of these materials has revealed dire environmental issues. [6][7][8][9] Thus, considerable research has focused on partially or completely biobased polyesters. [2][3][4] Such alternatives to incumbent polymers could appreciably improve the sustainability of the short-term packaging industry.…”

“…[25][26][27][28] The five-carbon diacid IA has been promulgated as one of the top twelve renewable chemicals available from biomass by the U.S. Department of Energy National Renewable Energy Laboratory because of its scalability, sustainability, and nontoxicity. Table 1 shows the polymerization results from a survey of eight different catalysts, including Brønsted acids (entries 1-3), Brønsted bases (entries 4-5), and Lewis acids (entries [6][7][8][9][10][11]. 30 This biosynthetic method yields 40 to 80 million kg per year 31 with a cost near $1.5 USD per kg.…”

The Present and the Future of Degradable Dendrimers and Derivatives in Theranostics

“…Alternating Polyester Dendrimers. Different types of dendrimers, called by some authors "alternating dendrimers", 51 can be produced in which the ester linkages alternate with other types of linkages, if orthogonal coupling methods are used in alternation. 48,51,52 The alternation of click reactions with ester formation using two different AB 2 dendrons (Figure 4a.1) for the accelerated synthesis of the dendrimers was reported by Antoni et al 53 Because these orthogonal reactions do not require protecting groups and, thus, activation or deprotection steps are not needed, only five steps led to the preparation of a G4 dendrimer (Figure 4a.2).…”

Polyester Dendrimers: Smart Carriers for Drug Delivery

“…In addition, polyester dendrimers have labile ester functionalities which are steadily hydrolyzed in vivo to release entrapped or covalently attached drugs. Higher generation polyester dendrimers can easily be prepared with facile synthesis of other dendrimers and a variety of methods have been reported for ester bond formation [126][127][128][129][130][131][132][133][134][135]. The synthesis of polyester dendrimers in general [135] and those derived from bis-2,2-hydroxymethylpropanoic acid (bis-HMPA) in particular [58] have been reviewed.…”

“…Higher generation polyester dendrimers can easily be prepared with facile synthesis of other dendrimers and a variety of methods have been reported for ester bond formation [126][127][128][129][130][131][132][133][134][135]. The synthesis of polyester dendrimers in general [135] and those derived from bis-2,2-hydroxymethylpropanoic acid (bis-HMPA) in particular [58] have been reviewed. A recent attractive strategy is the use of uronium-based coupling agents, TBTU [136], TATU [137], and COMU [138] to promote ester bond formation between carboxylic acid dendrons and polyalcoholic cores [139].…”