Manganese carbonyl compounds as hydrosilation catalysts for organoiron acyl complexes

Abstract

Manganese acyl complexes L(CO){sub 4}MnCOR (L = CO, R = CH{sub 3}, Ph; L = PPh{sub 3}, PEt{sub 3}, R = CH{sub 3}) are effective catalysts (2-5%) for hydrosilating FpCOR compounds (R = CH{sub 3}, Ph; Fp = Fe(CO){sub 2}({eta}{sup 5}-C{sub 5}H{sub 5})) with monohydro-, dihydro-, and trihydrosilanes. Fp({alpha}-siloxyalkyl) complexes FpCH(CH{sub 3})OSiR{prime}{sub 3} (SiR{prime}{sub 3} = SiEt{sub 3}, SiMe{sub 2}Ph, SiHPh{sub 2}, SiHEt{sub 2}), (FpCH(CH{sub 3})O){sub 2}SiR{prime}{sub 2} (R{prime} = Et, Ph), FpCH(Ph)OSiHPh{sub 2}, and (FpCH(CH{sub 3})O){sub 3}SiPh are isolated (after column chromatography on silica gel or on polystyrene (size-exclusion) beads) and fully characterized. Substituted manganese acetyl compounds L(CO){sub 4}MnCOCH{sub 3} are extremely active catalysts that quantitatively transform FpCOCH{sub 3} and dihydrosilanes R{prime}{sub 2}SiH{sub 2} (R{prime} = Et, Ph) to Fp({alpha}-siloxyalkyl) complexes FpCH(CH{sub 3})OSiHR{prime}{sub 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){sub 5}MnSiMe{sub 3}, Mn{sub 2}(CO){sub 10}, (CO){sub 5}MnCH{sub 3}, and (CO){sub 5}MnCHPh(OSiHR{prime}{sub 2}), also catalyze the hydrosilation of FpCOCH{sub 3}.