A new family of phosphine ligands bearing a bulky carbazolyl scaffold is described. With the combination of ligand 2a and Pd(OAc)2, difficult tri-ortho-substituted biaryl couplings are accomplished smoothly. In particular, the catalyst loading as low as 0.02 mol% of Pd for non-activated 2,6-disubstituted aryl chloride coupling can be achieved.
Mixed phosphine/N-heterocyclic carbene palladium complexes: synthesis, characterization and catalytic use in aqueous Suzuki–Miyaura reactions
作者:Thibault E. Schmid、Dale C. Jones、Olivier Songis、Olivier Diebolt、Marc R. L. Furst、Alexandra M. Z. Slawin、Catherine S. J. Cazin
DOI:10.1039/c2dt32858e
日期:——
series of N-heterocycliccarbene (NHC)/PR3 palladium(II) and palladium(0) complexes has been synthesized and fully characterized. X-ray crystallographic data have allowed comparison of ligand steric properties. The NHC ligand was found to vary its steric properties as a function of the phosphine co-ligand. These complexes display interesting catalytic properties in the Suzuki–Miyaurareaction performed
Arynes are found to be facilely inserted into bis(pinacolato)diboron by using a platinum–isocyanide catalyst, affording diverse 1,2-diborylarenes, which can be converted into o-terphenyls via Suzuki–Miyaura coupling reaction.
A highly general, active, and stable catalytic system was realized in the palladium-catalyzed Suzuki-Miyaura reactions of sterically hindered aryl bromides with arylboronic acids using biphenylene-substituted di-tert-butylruthenocenylphosphine (R-Phos) as a supporting ligand.