Dendrimer applications

Bieniarz, C. Dendrimers Applications to Pharmaceutical and Medicinal Chemistry, Vol. 18, Marcel Dekker, p. 55, (1998). 

Bieniarz, C. Dendrimers applications to pharmaceutical and medicinal chemistry, in Swarbrick, J. and Boylan, J. C. (eds) Encyclopedia of Pharmaceutical Technology, v. 18, Marcel Dekker Inc, New York, 1999, pp. 55-89. 

This section describes synthetic approaches to the various classes of organosilicon dendrimers. Applications of these materials will also be discussed. In this review, specific dendrimers will be labeled G-X, where is equivalent to the number of layers (or generations, G) around the core, and X represents the endgroups bound to each silicon atom in the outermost layer. This labeling system does not take into account the core or the branching of the dendrhner. Since carbosilane dendrimers are by far the most well-studied of the silicon-based dendrimers, they will be discussed first. 

Flomenbom, O., Amir, R.J., Shabat, D., and Klafter, J. (2005) Some new aspects of dendrimer applications. Journal of... 

Another fascinating area of dendrimer applications is based on their high surface functionality. No other class of synthetic or natural compounds contains so many reactive terminal groups per molecule as do the dendrimers. This provides major directions for possible exploitation. First, dendrimers can be modified in various ways with reagents of small molecular weight. It is thus possible to produce dendrimers with so-called ejt -modified or differentiated surfaces. For example, attachment of catalytic or biological receptor sites suggests many possible applications. Furthermore, the dendrimer interiors may be modified in many yet specific ways. Interior differentiated dendrimers with different combinations... 

Structure, physical properties, and applications of dendrimers including heterocyclic fragments 99CRV1665. 

Seebach et al., who first developed the TADDOL ligands [53, 67], have also developed a number of polymer- and dendrimer-bound TiCl2-TADDOLate catalysts derived from the monomeric TADDOLs [68]. Application of 10mol% of this type of catalysts, derived from polymers and dendrimers of 27 and 28, respectively, in the... 

Monomers of die type Aa B. are used in step-growth polymerization to produce a variety of polymer architectures, including stars, dendrimers, and hyperbranched polymers.26 28 The unique architecture imparts properties distinctly different from linear polymers of similar compositions. These materials are finding applications in areas such as resin modification, micelles and encapsulation, liquid crystals, pharmaceuticals, catalysis, electroluminescent devices, and analytical chemistry. 

Due to dieir compact, branched structure and to die resulting lack of chain entanglement, dendritic polymers exhibit much lower melt and solution viscosity dian their lineal" counterparts. Low a-values in die Mark-Houwink-Sakurada intrinsic viscosity-molar mass equation have been reported for hyperbranched polyesters.198 199 Dendrimers do not obey diis equation, a maximum being observed in die corresponding log-log viscosity-molar mass curves.200 The lack of chain entanglements, which are responsible for most of the polymer mechanical properties, also explains why hyperbranched polymers cannot be used as diermoplastics for structural applications. Aldiough some crystalline or liquid... 

The data presented in Figure 8 graphically illustrate the tremendous and rapid growth in interest in FOSS chemistry, especially for patented applications. This looks set to continue with current applications in areas as diverse as dendrimers, composite materials, polymers, optical materials, liquid crystal materials, atom scavengers, and cosmetics, and, no doubt, many new areas to come. These many applications derive from the symmetrical nature of the FOSS cores which comprise relatively rigid, near-tetrahedral vertices connected by more flexible siloxane bonds. The compounds are usually thermally and chemically stable and can be modified by conventional synthetic methods and are amenable to the usual characterization techniques. The recent commercial availability of a wide range of simple monomers on a multigram scale will help to advance research in the area more rapidly. 

The field of synthetic enzyme models encompasses attempts to prepare enzymelike functional macromolecules by chemical synthesis [30]. One particularly relevant approach to such enzyme mimics concerns dendrimers, which are treelike synthetic macromolecules with a globular shape similar to a folded protein, and useful in a range of applications including catalysis [31]. Peptide dendrimers, which, like proteins, are composed of amino acids, are particularly well suited as mimics for proteins and enzymes [32]. These dendrimers can be prepared using combinatorial chemistry methods on solid support [33], similar to those used in the context of catalyst and ligand discovery programs in chemistry [34]. Peptide dendrimers used multivalency effects at the dendrimer surface to trigger cooperativity between amino acids, as has been observed in various esterase enzyme models [35]. 

The first true dendrimers were the polyamidoamines (PAMAMs). They are also known as starburst dendrimers, and the term starburst is a trademark of the Dow Chemical Company, who have commercialized these materials for a range of applications. These dendrimers use ammonia as the core molecule, and this is reacted with methyl acrylate in the presence of methanol, after which ethylenediamine is added. This is shown in Scheme 9.2. 

G. Newkome, C.N. Moorefield, F. Vogtle and N.C. Moorefield, Dendrimers and Dendrons Concepts, Synthesis, Applications, Wiley-VCH, Weinheim, Berlin, 2001. 

C.A. Schalley and F. Vogtle (eds), Dendrimers Functional and Hyperbranched Building Blocks, Photophysical Properties, Applications in Materials and Life Sciences, Vol 5, Springer-Verlag GmbH, Berlin and Heidelberg, 2003. 

Perrier RJ (2001) Direct Conversion of 5,6-Unsaturated Hexopyranosyl Compounds to Functionalized Glycohexanones. 215 277-291 Frey H, Schlenk C (2000) Silicon-Based Dendrimers. 210 69-129 Forster S (2003) Amphiphilic Block Copolymers for Templating Applications. 226 1-28 Frullano L, Rohovec J, Peters JA, Geraldes CFGC (2002) Structures of MRI Contrast Agents in Solution. 221 25-60... 

Yokoyama S, Otomo A, Nakahama T, Okuno Y, Mashiko S (2003) Dendrimers for Optoelectronic Applications. 228 205-226... 

Bauer RE, Grimsdale AC, Mullen K (2005) Functionalised Polyphenylene Dendrimers and Their Applications. 245 253-286 Beaulac R, see Bussito G (2004) 241 97-118... 

Cornils B (1999) Modern Solvent Systems in Industrial Homogeneous Catalysis.206 133-152 Crooks RM, Lemon III BI, Yeung LK, Zhao M (2001) Dendrimer-Encapsulated Metals and Semiconductors Synthesis, Characterization, and Applications. 212 81 -135 Croteau R, see Davis EM (2000) 209 53 - 95 CurranDP, see Maul JJ (1999) 206 79-105... 

In this chapter, some experimental tips on the synthetic studies of CPOs are reviewed. Because this class of materials has specific properties associated with the large size of molecules, several special methodologies should be dealt with, which are applicable to the dendrimers. 

Newkome GR, Moorefield CN, Vdgtle F (2001) Dendrimers and dendrons, concept, synthesis, applications. Wiley-VCH, Weinheim... 

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