Dendrons aliphatic ether

Frechet et al. subsequently prepared dendronized oligothiophenes 5.68 and 5.69 up to a nonamer. The aliphatic ether dendrons were attached either to the a-position of a terminal or to the P-position of a central thiophene unit (Chart 1.77) [511]. The syntheses were performed by iterative NBS brominations and Pd°-catalyzed Stille-type coupling reactions. These materials revealed that the attachment of dendrons... 

Fig. 4.62 Chiral-core dendrimers of various generations (according to Seebach et al.), consisting of a chiral tris(hydroxymethyl) methane core unit and poly (aryl ether) dendrons (GO, Gl, or G2), which are linked to the core either directly (A), via an aliphatic spacer (B), or via an aromatic spacer (C)...

Protection of the peripheral phenolic groups as benzyl ethers was selected so that regioselective cleavage of these ethers in the presence of interior aliphatic ether linkages could be effected to liberate phenolic groups at some later stage. These functionalized dendrons were coupled to various anchor cores to produce... 

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