Conversion of the allenyl complexes (PPh 3) 2Pt(μ-η 1:η 2α,β-C(R)CCH 2)Ru(CO)Cp to the hydrido-alkylidene complexes (PPh 3) 2Pt(μ-H)(μ-η 1:η 1-C(R)C(O)CH 3)Ru(CO)Cp (R=H, Ph) by reaction with water under heterogeneous conditions

Abstract

Treatment of (PPh 3) 2Pt((μ-η 1:η 2 α,β-C(R)CCH 2)Ru(CO)Cp (R=H ( 1), Ph ( 2)) in CH 2Cl 2 or CHCl 3 solution with deactivated alumina, silica or Florisil affords the corresponding hydridoalkylidene complexes (PPh 3) 2Pt(μ-H)(μ-η 1:η 1-C(R)C(O)CH 3)Ru(CO)Cp (R=H ( 3), Ph ( 4)) in less than or approximately 50% yield. The conversion of 1 to 3 is promoted by use of acidic alumina. There is no reaction in the oxygenated solvents THF or diethyl ether, or in CHCl 3–H 2O without the added solid support. Activated alumina suppresses this ‘hydration’ reaction, as does added free radical inhibitor nitrosobenzene or benzoquinone, all in CH 2Cl 2 or CHCl 3. Complexes 3 and 4 were characterized by IR and 1H, 13C{ 1H} and 31P{ 1H} NMR spectroscopy and elemental analysis, and the structure of 3 was determined by single crystal X-ray diffraction analysis.