Biphenyl diboronic ester

Several years later, Reynolds and co-workers [179] extended this work to prepare another sulfonated poly(p-phenylene) using the same approach by replacing 1,4-diboronic acid with 4,4 -biphenyl diboronic ester ... 

The synthesis of poly(p-phenylene) via the homocoupling of p-hro-mophenylboronic acids was first reported by the Max Planck Institut. After this discovery, various new poly(p-phenylenes) were synthesized. A rigid-rod poIy(p-phenylene) was prepared by cross-coupling a biphenyl diboronic ester and a dibromide in aqueous DMF in the presence of a water soluble palladium catalyst (Eq. 78). The... 

The complexation of aldoses with cholesterol-derived boronic acids has been reviewed, and the changes in UV absorption and fluorescence intensity of a stilbene-type boronic acid on complexation with aldoses, especially D-fructose, have been studied with a view to their use in sugar-detection. Similar work has been carried out with diboronic acids derived from biphenyl and a -functionalized diaza-18-C-6 crown ether.A carbohydrate boronic acid derivative with liquid crystal properties referred to in Chapter 6, and further reports on boronate esters are noted in Chapter 17. 

As was seen, coordinating amines can be built into the monomer structure to enhance the stability of the ester linkage by generating tetra-coordina te boron. Polymers based on this design have been created using amino-substituted biphenyl-4,4 -diboronic acid interacting with saccharides (Fig. 29). The biphenyl moiety was incorporated to provide a spectroscopic handle to probe... 

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