Catalysts for cross-coupling reactions

Commercially available Pd(PtBu3)2 is a unique, air-stable 14e Pd° complex, an excellent catalyst for cross-coupling reactions of aryl chlorides. The ability of P Bu3 to stabilize such a coordin-atively unsaturated, extremely reactive, and yet easily manageable form of Pd° is one of the most amazing and fruitful recent findings in Pd-based catalysis. The cross-coupling of arylzinc reagents with aryl or vinyl chlorides can be readily accomplished with as little as 0.03% of this catalyst. Both electron-rich and sterically hindered substrates are welcome in this protocol.404... 

Steel PG, Teasdale CWT. Polymer supported palladium A-heterocyclic carbene complexes long lived recyclable catalysts for cross coupling reactions. Tetrahedron Lett 2004 45 8977-8980. 

Kantchev EAB, O Brien CJ, Organ MG (2007) Palladium complexes of A-heterocyclic carbenes as catalysts for cross-coupling reactions - a synthetic chemist s perspective. Angew Chem Int Ed 46 2768-2813 Kerr MS, Rovis T (2004) Enantio selective synthesis of quaternary stereocenters via a catalytic asymmetric Stetter reaction. J Am Chem Soc 126 8876-8877 Kerr MS, Read de Alaniz J, Rovis T (2002) A highly enantio selective catalytic intramolecular Stetter reaction. J Am Chem Soc 124 10298-1029 Kerr MS, Read de Alaniz J, Rovis T (2005) An efficient synthesis of achiral and chiral 1,2,4-triazolium salts bench stable precursors for A-heterocyclic carbenes. J Org Chem 70 5725-5728... 

Hayashi, T., Konishi, M., Kumada, M. Dichloro[1,1 -bis(diphenylphosphino)ferrocene]palladium(ll) an effective catalyst for cross-coupling reaction of a secondary alkyl Grignard reagent with organic halides. Tetrahedron Lett. 1979,1871-1874. 

Wu J, Zhang L, Gao K (2006) RhCl(PPh3)3/DPPF a useful and efficient catalyst for cross-coupling reactions of activated alkenyl tosylated with arylboronic acids. Eur J Org... 

Pd-N-heterocyclic carbene catalysts for cross-coupling reactions 06AA97. 

Phosphinocarbene or 2 -phosphaacetylene 4, which is in resonance with an ylide form and with a form containing phosphoms carbon triple bond, is a distillable red oil. Electronic and more importantly steric effects make these two compounds so stable. Carbene 4 adds to various electron-deficient olefins such as styrene and substituted styrenes. Bertrand et al. have made excellent use of the push-pull motif to produce the isolable carbenes 5 and 6, which are stable at low temperature in solutions of electron-donor solvents (THF (tetrahydrofuran), diethyl ether, toluene) but dimerizes in pentane solution. Some persistent carbenes are used as ancillary ligands in organometallic chemistry and in catalysis, for example, the ruthenium-based Grubbs catalyst and palladium-based catalysts for cross-coupling reactions. 

The polymeric imide could then be reacted with primary amines or ammonia to form ammonium salts for a subsequent reactions with a carboxylic acid in the presence of a coupling reagent. It could then be converted to amides or functionalized as a uranium salt for use as polymer-supported peptide coupling. In addition, the anhydride was also reacted with di(2-pyrldyl)methylamine and formed a recoverable palladium catalyst for cross-coupling reactions that could take place in water. 

Kantchev, E.A.B., O Brien, C.J. and Organ, M.G. (2007) Palladium complexes of N-heterocyclic carbenes as catalysts for cross-coupling reactions - a synthetic chemist s perspective. Angew. Chem. Int. Ed., 46, 2768-813. 

Hillier, A.C., Nolan, S.P. Palladium/nucleophilic carbene catalysts for cross-coupling reactions.Plat. Met. Rev. 46, 50 (2002)... 

Many of the practical routes to the synthesis of diaryl ethers are focused on the use of transition metal complexes as catalysts for cross-coupling reactions [68-70]. Copper has played a central role in this chemistry and has been used extensively in the synthesis of diaryl ethers. 

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