A Method for the Synthesis of Carbene Precursors from Aldehydes and the Metalates (η5-C5H5)(CO)2Fe- and (η5-C9H7)(CO)2Fe-

Abstract

Nucleophilic addition of the metalate Cp(CO)2Fe-M+ (M = Na, K) to aldehydes RCHO (R = Ph, CH3, p-OCH3Ph, p-ClPh, p-CH3Ph, p-CF3Ph, o-OCH3Ph, and CHC(CH3)2) and subsequent capture with ClSi(CH3)3 provided the (α-siloxyalkyl)iron complexes Cp(CO)2FeCH(OSiMe3)R in 42−79% yield. This new reaction was extended to the indenyl-ligated metalate In(CO)2Fe-Na+ with several aldehydes RCHO (R = Ph, CH3, p-OCH3Ph). Treatment of the (α-siloxyalkyl)iron complexes with trimethylsilyl triflate at between −25 and −78 °C, in the presence of alkenes, gave cyclopropanes through iron carbene complexes.