Ruthenium titanocene and ruthenium titanium half-sandwich bimetallic complexes in catalytic cyclopropanation

The reaction of the phosphine functionalised titanium half-sandwich complexes 7, 9 and 10 with the binuclear complex (p-cymene)RuCl₂]₂ allowed the access to three new early-late bimetallic complexes (p-cymene)(μ-η⁵:η¹-C₅H₄(CH₂)_nPR₂)TiX₃]RuCl₂ (11-13). The structure of 11 (n = 0, X = Cl) has been confirmed by X-ray diffraction. The ruthenium titanium half-sandwich bimetallic complexes so formed and the ruthenium titanocene analogues 4-6 catalyse the addition of ethyl diazoacetate to styrene with high selectivity toward cyclopropanation versus metathesis contrary to the monometallic complexes (p-cymene)RuCl₂PR₃.