MANGANESE CARBONYL-COMPOUNDS AS HYDROSILATION CATALYSTS FOR ORGANOIRON ACYL COMPLEXES

Manganese acyl complexes L(CO)4MnCOR [L = CO, R = CH3, Ph; L = PPh3, PEt3, R = CH3] are effective catalysts (2-5%) for hydrosilating FpCOR compounds [R = CH3, Ph; Fp = Fe(CO)2(eta-5-C5H5)] with monohydro-, dihydro-, and trihydrosilanes. Fp(alpha-siloxyalkyl) complexes FpCH(CH3)OSiR'3 (SiR'3 = SiEt3, SiMe2Ph, SiHPh2, SiHEt2), [FpCH(CH3)O]2SiR'2 (R' = Et, Ph), FpCH(Ph)OSiHPh2, and [FpCH(CH3)O]3SiPh are isolated [after column chromatography on silica gel or on polystyrene (size-exclusion) beads] and fully characterized. Substituted managanese acetyl compounds L(CO)4MnCO-CH3 are extremely active catalysts that quantitatively transform FpCOCH3 and dihydrosilanes R'2SiH2 (R' = Et, Ph) to Fp(alpha-siloxyalkyl) complexes FpCH(CH3)OSiHR'2. The manganese acetyl catalysts endure (within NMR spectral detection limits) until all of the organoiron acyl substrate is consumed; only then do they undergo rapid hydrosilation. Other manganese complexes, including (CO)5MnSiMe3, Mn2(CO)10, (CO)5MnCH3, and (CO)5MnCHPh(OSiHR'2), also catalyze the hydrosilation of FpCOCH3.