1,3-Bis(2,6-diisopropylphenyl)imidazol-2-ylidene

Synthesis of the Pd complex and its activity in cross-coupling reactions

Typical procedure (synthesis of the palladium complex 1): A Schlenk flask is loaded with 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene (2.73 g), bis(2,4-pentanedionato)palladium (1.53 g) and anhydrous dioxane (50 mL). The mixture is stirred at room temperature for 2 h. After that time, 1.25 mL of 4M HCl in dioxane is injected in the solution and the mixture allowed stirring at room temperature for anther 2 h. The solvent is then evaporated in vacuum and diethyl ether is added until no more solid dissolved (20 mL). The solution is filtered and the solid washed with diethyl ether (2 x 10 mL). The solvent is evaporated in vacuum and the powder obtained dried under vacuum to yield 2.85 g (90 %) of the palladium complex 1 as a yellow microcrystalline material.

• O. Navarro, N. Marion, N. M. Scott, J. Gonzalez, D. Amoroso, A. Bell, S. P. Nolan, Tetrahedron 2005, 61, 9716.