Heck reactions Suzuki coupling

To date a number of reactions have been carried out in ionic liquids [for examples, see Dell Anna et al. J Chem Soc, Chem Commun 434 2002 Nara, Harjani and Salunkhe Tetrahedron Lett 43 1127 2002 Semeril et al. J Chem Soc Chem Commun 146 2002 Buijsman, van Vuuren and Sterrenburg Org Lett 3 3785 2007]. These include Diels-Alder reactions, transition-metal mediated catalysis, e.g. Heck and Suzuki coupling reactions, and olefin metathesis reactions. An example of ionic liquid acceleration of reactions carried out on solid phase is given by Revell and Ganesan [Org Lett 4 3071 2002]. 

Under all the conditions studied, addition of bare Si02-SH to Heck or Suzuki coupling reactions using a variety of bases, aryl halides and solvents resulted in complete cessation of the catalytic activity (35). These results suggest that catalysis with this precatalyst is also associated with labile palladium species that... 

Stewart and Whiting have reported a useful application of sequential Heck and Suzuki coupling reactions of a vinylborane pinacol ester with palladium catalysis to generate a tetraene (equation 147)260. 

The dibromo- (and diiodo-) stilbenes ate potentially useful monomers tor the synthesis of poly(p-phenylenevinylenes) via poly-Heck or poly-Suzuki coupling reactions. ... 

Ruhland, B. Bombrun, A. Gallop, M. A. Solid-Phase Synthesis of 4-Ary-lazetidin-2-ones via Suzuki and Heck Cross-Coupling Reactions, J. Org. Chem. 1997, 62, 7820-7826. 

Applications of Suzuki and Heck cross-coupling reactions were adopted by Gallop and coworkers [131] to prepare diverse biaryl- and styryl-substituted (3-lactams on solid support. The catalyst system, [PdCl2(dppf)]-TEA, was found to be efficient to promote C-C bond formation around a (3-lactam template (Schemes 26 and 27). 

Palladacycles [17] have been established as important class of catalysts, an unusual phosphine-free sulfur containing catalyst was introduced by Zim [18] et al. A phosphinite based palladacycle [19] proved to be very efficient in Suzuki coupling reactions. An N,P-Ligand type was synthesized by Kocovsky [20] et al. Tridentate pincer ligands [21] have been proved use-fill in the Heck reaction. Recent developments regarding Heck (22] and Suzuki [23] reactions have been reviewed by Fu and Littke. A new catalyst especially suitable for Heck couplings has been introduced by Beller [24] et al. 

Very promising results have also been observed using phosphonium-based ionic liquids in both Heck and Suzuki coupling reactions.[1012] Notably, good activities were obtained with arylchlorides as substrate, which in molecular solvents are often found to react only sluggishly, if at all. 

Figure 6.3 Carbapalladacycle tested in Heck and Suzuki-coupling reactions...

However, the real breakthrough in this area is due to the development of catalysis by transition metals, with the Heck, Suzuki, Sonogashira reactions and other related coupling process. ... 

Scheme 5.3-23 Pd-carbene catalyst as synthesized and applied for Heck and Suzuki coupling reactions in [BMIM][PF6] byShreeve and coworkers.

Heck, Suzuki, and Sonogashira coupling reactions [19], The same group later described an scC02-soluble nonfluorinated catalyst system formed by the combination of Pd(OAc)2 with PBu 3, which was applied to Heck and Suzuki coupling reactions [20],... 

Demir, S., Ozdemir, I. and Cetinkaya, B. (2006) Use of bis(benzimidazolium)-paUadium system as a convenient catalyst for Heck and Suzuki coupling reactions of aryl bromides and chlorides. Appl. Organomet. Chem., 20, 254-9. 

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