Suzuki cross-coupling reactions polymers

Han, Y. Walker, S. D. Young, R. N. Silicon Directed ipso-Substitution of Polymer Bound Arylsilanes Preparation of Biaryls via the Suzuki Cross-Coupling Reaction, Tetrahedron Lett. 1996, 37, 2703—2706. 

A polyethylene glycol-polystyrene graft copolymer palladium catalyst has been used in allylic substitution reactions of allyl acetates with various nucleophiles in aqueous media.58 Another polymer-bound palladium catalyst 40 was developed and used in a Heck coupling of allylic alcohols with hypervalent iodonium salts to afford the substituted allylic alcohols as the sole products under mild conditions with high catalytic efficiency.59 The same polymer-bound palladium catalyst has also been used for Suzuki cross-coupling reactions.60... 

Han Y, Walker SD, Young RN, Silicon directed ipso-substitution of polymer bound arylsilanes preparation of biaryls via the Suzuki cross-coupling reaction, Tetrahedron Lett., 37 2703-2706, 1996. 

Y. Zheng, P.D. Stevens, and Y. Gao Magnetic nanoparticles as an orthogonal support of polymer resins Applications to solid-phase Suzuki cross-coupling reactions. Journal of Organic Chemistry 71, 537-542 (2006)... 

Palladium species immobilized on various supports have also been applied as catalysts for Suzuki cross-coupling reactions of aryl bromides and chlorides with phenylboronic acids. Polymers, dendrimers, micro- and meso-porous materials, carbon and metal oxides have been used as carriers for Pd particles or complexes for these reactions. Polymers as supports were applied by Lee and Valiyaveettil et al. (using a particular capillary microreactor) [173] and by Bedford et al. (very efficient activation of aryl chlorides by polymer bound palladacycles) [174]. Buch-meiser et al. reported on the use of bispyrimidine-based Pd catalysts which were anchored onto a polymer support for Suzuki couplings of several aryl bromides [171]. Investigations of Corma et al. [130] and Plenio and coworkers [175] focused on the separation and reusability of Pd catalysts supported on soluble polymers. Astruc and Heuze et al. efficiently converted aryl chlorides using diphosphino Pd(II)-complexes on dendrimers [176]. 

New developments in the Suzuki cross-coupling reaction include the application of microwave, polymer-bound catalysts, nanoparticles, and ionic liquids as reaction medium. A discussion of these methods exceeds the scope of this chapter. 

Suzuki cross-coupling has found applications in the preparation of specialty polymers, too. Rigid rod polymers may have very useful properties (the well-known Kevlar, poly(p-phenyleneterephtalamide) belongs to this family, too) but they are typically difficult to synthetize, characterize and process. Such materials with good solubility in organic solvents [38] or in water [39] were obtained in the reactions of bifunctional starting compounds under conventional Suzuki conditions with [Pd(PPh3)4] and [Pd(TPPMS)3] catalysts, respectively (Scheme 6.15). 

Discoveries made in the late 1970s of electrical conductivity in conjugated polymers spawned a monumental interest in the study of these materials, which are ideally suited for synthesis via cross-coupling reactions. Yamamoto was the first to realize this possibility with a regiochemicahy defined synthesis of poly(/ -phenylene) formed via the Kumada-Corriu protocol. Since then, various cross-coupling reactions have been applied in condensation polymerization reactions,with the Suzuki and Sonogashira protocols gaining the most widespread use. 

An all carbon conjugated ladder polymer (graphite ribbon) was synthesized by a novel electrophile-induced cyclization reaction to provide fused benzenoid aromatic hydrocarbon in quantitative yield [161]. Suzuki cross-coupling of dieneyne 105 with 1,4-didode-cylbenzene-2,5-diboronic acid (106) gave rigid-rod polymers 107, which was further treated with TFA to produce 108 graphite ribbon as a yellow/orange solid. 

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