Dick chemistry

The formation of triazole rings by the reactions of azides and acetylenes was first described by Huisgen and coworkers [48,49] and has recently been promoted as dick chemistry by Sharpless et al. [50,51]. This versatile [3 + 2] dipolar cycloaddition proved to be useful for the synthesis of hyperbranched polytriazoles via 1,3-dipolar polycydoaddition of AB2-type monomers 28 and 29 (Scheme 14) [52], The monomers exhibited very high reactivity the... 

Soluble supported catalysts of this class are also accessible. Thus, various thia-zolium, imidazolium and triazolium structures have been recently immobilized on PEG via dick chemistry [365], Thiazolium resins (151) were the most efficient catalysts (10mol.%) for the intramolecular Stetter reaction. Compound 154 (Scheme 10.23) was obtained in 81% with the supported catalyst whilst an 84% yield was obtained when the non-supported analog was employed. Imidazolium systems like 152 were also able to promote the carbene-catalyzed diastereoselective redox esterification. In this case, 155 was obtained with higher yields (77%) and stereoselectivities (18 1 E Z ratio) than when using the non-supported system (63% and 11 1). This can be associated with the positive influence of steric hindrance on the results of this reaction. 

J. Pyun, J.M.J. Frechet, K.B. Sharpless, V.V. Fokin, Efficiency and fidelity in a dick-chemistry route to triazole dendrimers by the copper(I)-catalyzed ligation of azides and alkynes, Angew. Chem. Int. Ed. Engl. 2004, 43, 3928-3932. 

Functionalization of MWCNTs by the layer-by-layer dick chemistry (LbL-CC) approach and further modification of the functionalized MWCNTs with fluorescent dye and polystyrene by click chemistry. Reprinted with permission from Zhang et al. 

The divasity of materials that can be appended to the CPMV coat protein using dick chemistry was furtha demonstrated when the Finn and Manchesta labs attached fullerenes (bucky-balls ) to the exterior surface of the virus. By using dick chemistry, the hydrophobic Cso molecules could be attached to the CPMV capsid, as well as the capsid of bacteriophage Q(3, allowing for solubilization of the highly hydrophobic fullerene. The modified capsids wae readily taken up by cdls, and the authors proposed that the buckyballs could be used as photosensitizers for cancer therapy in future applications. 

Model polymer networks and APCNs are two interesting forms of semisolid matter. The former have a perfect stmcture, their synthesis is rather challenging, but their preparation and studies have recently been boosted as a result of recent progress in the areas of controlled polymerization and dick chemistry. Research on APCNs also flourishes, a result of their rather easier synthesis and self-assembling properties that ensures many possible applications. 

However, there seems to be a change in judging the situation and due to the development of new techniques, such as highly efficient post-polymerization modification techniques such as dick chemistry. The recent state in the field of terpenes, terpenoids, and rosin has been reviewed. These t5q>es of biomass are of low cost, and have much potential for their utilization as organic feedstocks for green plastics. 

SCHEME 14.6 Covalent functionalizalion of SWCNTs via dick chemistry. Double bonds in NT... 

Co to http //now.brookscole.com/ cracolice3e and dick Chemistry Interactive for the module Chemical Change. 

Xu, L. Q., D. Wan, H. F. Gong, K. G. Neoh, E. T. Kang, and G. D. Fu. 2010. Qne-p>ot preparation of ferrocene-functionalized polymer brushes on gold substrates by combined surface-initiated atom transfer radical polymerization and "dick chemistry." 26 (19) 15376-15382. 

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