Polyglycerols, dendritic

Sequential hydroformylation/reductive amination of dendritic perallylated polyglycerols with various amines in a one-pot procedure to give dendritic polyamines in high yields (73-99%). Furthermore, the use of protected amines provides reactive core-shell-type architectures after deprotection. These soluble but membrane filterable multifunctional dendritic polyamines are of high interest as reagents in synthesis or as supports in homogeneous catalysis as well as nonviral vectors for DNA-transfection (Scheme 18) [65]. 

Transformations on this support included the synthesis of aminoketones from supported chloroketones as weU as biarylaldehydes after Suzuki cross-couphng reactions of supported bromo-benzaldehydes [21]. This dendritic polyglycerol was... 

Recently, Hebei and Haag reported on the immobilization of aryl boronic acids (62) on a dendritic polyglycerol support (15) (Fig. 7.8, M =8000 g mol ) (Scheme 7.10) [57]. This commercially available support was directly used and no additional... 

These features of these materials spurred the scientific community to utilize them in biomedical applications [49]. In particular, the synergy between their multivalency and size on the nanoscale enables a chemical smartness along their molecular scaffold that achieves environmentally sensitive modalities. These functional materials are expected to revolutionize the existing therapeutic practice. Dendritic molecules, such as polyamidoamine, polylysine, polyester, polyglycerol (PG), and triazine dendrimers, have been introduced for biomedical applications to amplify or multiply molecularly pathopharmacological effects [73]. 

Due to their highly biocompatible nature, dendritic PGs have a broad range of potential applications in medicine and pharmacology. The versatility of the polyglycerol scaffolds for application in the biomedical field has recently been reviewed [131], and a number of examples were described, therein, e.g., smart and stimuli-responsive delivery and release of bioactive molecules, enhanced solubilization of hydrophobic compounds, surface-modification and regenerative therapy, as well as transport of active agents across biological barriers (cell-membranes, tumor tissue, etc.). 

Haag et al. [43] have recently reported on the supramolecular immobilization of a perfluoro-tagged Pd catalyst on a dendritic polyglycerol ester with a perfluorinated shell and they have investigated its activity in Suzuki coup-... 

Fig. 13 a Synthesis of dendritic polyglycerol perfluorolkyl ester 18 from hyperbranched polyglycerol 17... 

Siegers C, Biesalski M, Haag R (2004) Self-assembled monolayers of dendritic polyglycerol derivatives on gold that resist the adsorption of proteins. Chem Eur J 10(11) 2831-2838... 

FIGURE 5.24 Sialic acid conjugated dendritic polyglycerol nanoparticles with diameters in the range of 60 nm efficiently block viral infections by polyvalent inhibition of the hemagglutinin in contrast to their smaller multivalent analog. Source Quadir and Haag [54]. Reproduced with permission from Elsevier. 

Figure 1 NMR spectra of hyperbranched polyglycerol recorded in inverse-gated (IG) mode, showing different linear, dendritic, and terminal units. Reprinted with permission from Sunder, A. Hanselmann, R. Frey, H. Mulhaupt, R. Macromolecules 32, 4240-4246. Copyright 1999 American Chemical Society.

Calderon Marcelo, Quadir Mohiuddin Abdul, Sharma Sunil Kumar, and Rainer Haag. Dendritic polyglycerols for biomedical applications. Adv. Mater. 22 no. 2 (2010) ... 

Chiral manganese salen catalysts have been widely used for the asymmetric oxidation of unactivated olefins. The dendritic polyglycerol-supported Mn-salen catalyst (44) was developed for the asymmetric epoxidation of the chromene derivative in a continuous membrane fiow reactor. This fiow system involves the continuous removal of the product (and unreacted substrate) from the high-molecular-weight dendritic catalyst (44) by filtration through a nanomembrane (Scheme 7.33). Under optimal conditions, 70% conversion with up to 92% ee was achieved [133]. In this system, however, the dendritic catalyst (44) worked as a homogeneous catalyst rather than a heterogeneous one. 

Similar approaches have also been used in the field of dendritic polymers. Calderon et al. (2009) prepared polymer-drug conjugates from dendritic polyglycerol and maleimide-bearing prodrugs (Tyagarajan et al., 2003 ... 

Calderon, M., Graeser, R., Kratz, F. and Haag, R. (2009) Development of enzymatically cleavable prodrugs derived from dendritic polyglycerol. Bioorg Med Chem Lett, 19,3725-3728. 

Istratov V, Kautz H, Kim YK, Schubert R, Frey H (2003) Linear-dendritic nonitmic poly (propylene oxide)-polyglycerol surfactants. Tetrahedron 59 4017-4024... 

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