Hyperbranched Macromolecules in Asymmetric Catalysis

Dendritic Encapsulation of Function: Applying Nature's Site Isolation Principle from Biomimetics to Materials Science

“…[73] The molecules, termed ªdendrizymesº, were designed to transfer the chiral information inherent in the dendrimer backbone over a long range to the asymmetric metal center. Whereas Bolm and co-workers used dendritic pyridyl alcohols (Scheme 15 a) for the asymmetric addition of diethylzinc to benzaldehyde, [74] Yoshida et al reported on dendrimers with binaphthol core as Scheme 15. Interestingly, in one case a 1,3,5-branched ligand led to a rate acceleration whereas the 1,2,5-isomer showed a rate retardation.…”

Dendritic Oligoethers

“…Such insoluble, dendrimer bound catalysts possess higher durability and also higher catalytic activities than those of conventional polymer bound catalysts. Similarly, Fréchet's dendrons 121 with a chiral pyridinol focal functionality can also be used to promote the enantioselective addition of Et 2 Zn to benzaldehyde [75]. Other dendritic ligands having the catalytic groups located at the focal point or near the central core included chiral binaphthol derived oligoether dendrons 122 [76] and tertiary amine-based oligoether dendrimers 123 [77], which were employed to effect the enantioselective addition of allyl stanane to benzaldehyde in the presence of titanium tetrapropoxide and the nitroaldol reaction, respectively.…”

Mean first passage time for random walk on dual structure of dendrimer

“…As a representative network, dendrimer (also called Cayley tree) [30][31][32][33][34] has extensive applications in different fields, including medicinal and diagnosis [35,36], drug delivery system [37,38], light harvesting [39,40] and electronic applications [41]. Random walks on dendrimer have been widely studied [42][43][44][45].…”