Triphenylphosphine complexes of palladium( II) acetate are well known to catalyse the alkoxycarbonylation of propyne to methacrylate esters. 1 Recent studies have shown that this reaction is more effectively catalysed by analogous palladium complexes of phenylphosphabicyclononanes (PPBNs), and that the 4,2,1-PPBN isomer (1a) produces a significantly more active catalyst than the 3,3,1-PPBN isomer (1b). 2 These observations prompted a closer investigation of the co-ordination ...
