An evaluation of phosphine and carbene adducts of phosphite- and phosphinite-based palladacycles in the coupling of alkyl bromides with aryl boronic acids

A range of palladacyclic catalysts and their phosphine and carbene adducts were tested in the Suzuki coupling of an alkyl bromide with phenylboronic acid and showed modest activity in some cases. Unlike with aryl halide substrates it appears that there is no particular benefit in the use of palladacycles as the palladium source. Initial data indicate that the rate determining step is not the oxidative addition of the alkyl halide substrate, but rather lies later in the catalytic cycle

Ruthenium PCP-bis(phosphinite) pincer complexes

The reactions of [RuHCl(CO)(PPh3)(3)] with resorcinol bis(phosphinite) pincer ligands lead to complexes of the general formula [RuCl(PCP)(CO)(PPh3)]; the crystal structure of one example has been determined. The structures of the bulky resorcinol 2-methyl4,6-di-tert-butyl resorcinol and its mono-diisopropylphosphinite derivative were also determined. Reactions of [RuCl2(PPh3)(3)] with resorcinot bis(phosphinite) ligands yield complexes of the type [RuCl(PCP)(PPh3)], while the reaction of C6H-2-Me-4,6-'Bu-2-1,3-(OPPh2) with [RuHCl(CO)(PPh3)(3)] provides a PCP-pincer complex in which the ligand has undergone 2-methyl C-H activation