Cobalt bromide-triphenylphosphine catalyst

TRIMETHYLPENTANAL, 51, 4 TRIMETHYLSILYL AZIDE, 50, 107 Triphenylphosphine-cobalt(II) bromide, catalyst, 53, 30,... 

As mentioned in the chapter on the reaction mechanism, the anion, especially of Ni-salts, is important in affecting the reaction course. The catalytic efficiency of the nickel halides strongly increases in the series fluoride, chloride, bromide, iodide [374—376]. The molar ratio of cobalt or nickel to iodine is also very important [414]. As in the hydroformylation reaction, metal carbonyls substituted by phosphine ligands are very reactive [377, 1009], and especially modified rhodium and palladium catalysts [1021, 1045] allow reactions under mild conditions. Thus, the nickel bromide triphenylphosphine allyl bromide complex shows an increased reactivity in the carbonylation of acetylenes. On the other hand, carbonyls substituted by phosphine ligands are also readily soluble in the reaction mixture [345, 377]. 

Cobalt(II) bromide-triphenylphosphine, catalyst, 53,30,32 Condensation, of p-acetylbenzenedi-azonium bromide with acrylic acid, 51,1... 

---