Preparation of hydrido(vinylidene)ruthenium(II) complexes and a one-pot synthesis of Grubbs-type ruthenium carbenes

摘要

Treatment of the hydrido(dihydrogen) compound [RuHCl(H-2)(PCy3)(2)] 1 with alkynes RC≡ CH (R = H, Ph) afforded the hydrido(vinylidene) complexes [RuHCl(=C=CHR)(PCy3)(2)] 2, 3 which react with HCl or [HPCy3]Cl to give the corresponding Grubbs-type ruthenium carbenes [RuCl2(=CHCH2R)(PCy3)(2)] 4, 5. The reaction of 2 (R = H) with DCl, or D2O in the presence of chloride sources, led to the formation of [RuCl2(=CHCH2D)(PCy3)(2)] 4-d(1). Based on these observations, a one-pot synthesis of compounds 4 and 5 was developed using RuCl3• 3H(2)O as the starting material. The hydrido(vinylidene) derivative 2 reacted with CF3CO2H and HCN at low temperatures to yield the carbene complexes [RuCl(X)(=CHCH3)(PCy3)(2)] 6, 7, of which 7 (X = CN) was characterized crystallographically. Salt metathesis of 2 with CF3CO2K and KI led to the formation of [RuH(X)(=C=CH2)(PCy3)(2)] 8, 9. The bis(trifluoracetato) and the diiodo compounds [RuX2(=CHCH3)(PCy3)(2)] 10, 11 as well as the new phosphine P(thp)(3) 12 (thp = 4-tetrahydropyranyl) and the corresponding complex [RuCl2(=CHCH3){P(thp)(3)}(2)] 14 were also prepared. The catalytic activity of the ruthenium carbenes 4-7, 10, 11 and 14 in the olefin cross-metathesis of cyclopentene and allyl alcohol was investigated.