Synthesis of enol esters catalysed by 'early–late' Ti–Ru complexes

Abstract The titane–ruthenium heterobimetallic compounds ( p -cymene)[(η 5 -C 5 H 5 )(μ-η 5 :η 1 -C 5 H 4 (CH 2 ) m PR 2 )TiCl 2 ]RuCl 2 4 – 6 have been revealed to be quite good catalysts for the addition of formic acid to 1-hexyne and phenylacetylene. These preliminary results led us to synthesize new tetrametallic complexes 10 – 12 via the reaction of the titanocene phosphanes 1 – 3 with the polymer [Ru(CO) 2 (μ-O 2 CH)] n . Their catalytic ability for the enol esters formation has been studied.