Synclinal and anticlinal isomers of the iron methoxycarbene complex [{η5-C5Me5)Fe(CO)2(CHOMe)]+; access to functional compounds

Abstract

The methoxymethyl complex (η⁵-C₅Me₅)Fe(CO)₂(CH₂OMe)(2) undergoes hydride abstraction with Ph₃C⁺PF₆^– at –80 °C and affords the secondary methoxycarbene complex [(η⁵-C₅Me₅)Fe(CO)₂(CHOMe)]⁺PF₆^–(1) as a mixture of two geometric isomers of which the syn form isomerizes upon warming; complex (1) adds PPh₃ yielding quantitatively [(η⁵-C₅Me₅)Fe(CO)₂(CHOMePPh₃)]⁺PF₆^–(3), and converts Me₂PhSiH into Me₂PhSiCH₂OMe (4), giving in the presence of the appropriate alkenes, the alkenes, complexes [(η⁵-C₅Me₅)Fe(CO)₂(CH₂CHR)]⁺PF₆^–(5).