Di-t-butyl(ferrocenylmethyl)phosphine: air-stability, structural characterization, coordination chemistry, and application to palladium-catalyzed cross-coupling reactions

Di-t-butyl(ferrocenylmethyl)phosphine (1) has been isolated and structurally characterized. This ligand was found to be reasonably air stable as a solid and it has been shown to possess electron donating ability similar to that of tri-i-propylphosphine. A palladium catalyst bearing this ligand performed room temperature Suzuki–Miyaura coupling reactions with aryl bromides. Modest Heck coupling reactivity with aryl bromides was also observed at 100 °C. Complexation of 1 with Pd2(dba)3 led to formation of (1)2Pd0. Addition of 4-bromoanisole to solutions containing both 1 and Pd2(dba)3 led to formation of an oxidative addition product when 1:Pd ratios were ⩽1. With a 2:1 ratio of 1:Pd, monophosphine complex formation and oxidative addition were significantly inhibited.