Divergent strategy

A recently developed technique that has found extensive use in the characterization of dendrimers, specifically in determining the purity and monodispersity of these novel materials, has been matrix-assisted laser desorption/ionization (MALDI) mass spectrometry [16,17]. For dendrimers grown by the divergent strategy, incomplete functionalization of the periphery can lead to subsequent failure sequences and loss of strict dendritic growth. Observation and quantification of these defects is extremely difficult by other techniques, however MALDI mass spectrometry has been successfully employed by a variety of authors to... 

Seyferth and coworkers 104 prepared a series of Si-based dendrimers up to the fourth generation. Employing the tetravalent nature of silicon, these macromolecules possessed a tetrahedral, four-directional core, as well as 1 — 3 branching centers. The divergent strategy (Scheme 4.52) utilized two repetitive transformations displacement of halide at silicon with vinylmagnesium bromide (vinylation) and Pt-catalyzed alkyl trichlorosilane formation (hydrosilylation). 

Generally speaking, plants may follow two major ecologically classical and diverging strategies imder UV light pressure as under any other stress tolerance and avoidance. 

Streb, P., Shang, W., Feierabend, J., Bligny, R, 1998. Divergent strategies of photoprotection in high-mountain plants. Planta 207 313-324. 

In response to the often tedious and purification intensive iterative dendrimer syntheses, many researchers have sought accelerated approaches that combine the convergent and divergent strategies. 

As monomeric building blocks for a divergent strategy, we used several benzylic bromides (17-21) and the isophthalate 22 because each could... 

Schemes 7 a-c show the dendritic molecules that resulted from this divergent strategy.12-15...

Glycodendrimers can be synthesized by both convergent and divergent strategies. Ideally, they can be simply prepared by conjugation of active carbohydrate derivatives onto preformed dendrimers (Scheme 11). Given the commercial availability of poly(amidoamine) (PAMAM, 56) and poly(propyleneimine) (Dab, 57) dendrimers, these amine-ending dendrimers are the most heavily exploited. 

Recently, different strategies have been studied to prepare enantiopure metallo-dendrimers. Constable [76] proposed a divergent strategy starting from a chiral... 

Thomas, K.M. Naduthambi, D. Tririya, G. Zondlo, N.J. Proline editing a divergent strategy for the s3mthesis of conformationally diverse peptides. Org. Lett. 2005, 7, 2397-2400. 

Fig. 8 Divergent strategy for the total syntheses of cemuane-type and quinolizidine-type Lycopodium alkaloids...

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