The extremely rapid acid-catalysed isomerizations of carbonyl–Mo or –W tertiary phosphine complexes: convenient syntheses of fac- or mer-isomers

Abstract

Acid, at a concentration frequently present in solvents such as dichloromethane, causes rapid interconversion of fac- and mer-[W(CO)₃(dppm-PP′)L](dppm = Ph₂PCH₂PPh₂, L = PEt₃ or PEt₂Ph)via a 7-co-ordinate hydride intermediate, [WH(CO)₃(dppm-PP′L]⁺: convenient syntheses are developed, based on these protonation reactions, including the conversion of fac-[Mo(CO)₃(dppm-PP′)(dppm-P)] into the more useful mer-isomer.