Reactions of (CO)2(η5-C5H5)Fe Alkyls and Ph3C+ BF4 : A Search for Hydrogen-Atom Abstraction following One-Electron-Transfer

Abstract The reaction products of Ph3C+BF4- (2) and (CO)2- (η5-C5H5)Fe-(2-cyclopropylethyl) (1), -neopentyl (10), and -(1-norbornyl-carbinyl) (13) under N2 and under CO have been determined in an effort to detect evidence of hydrogen-atom abstraction from the 17e, Fe(III) cation-radical intermediate produced by one-electron transfer to the starting cation. None was observed. Labeling studies reveal that migratory CO insertion to produce (CO)2(η5-C5H5)FeCO(2-cyclo-propylethyl) (8) is accompanied by β- not α-hydride abstraction to form [(CO)2(η5-C5H5)Fe(η2-cyclopropylethene)]+BF4-(3) when 1 reacts with 2 under CO. The insertion is catalytic in 2. Hydrogen is not lost from 10 or 13 under these conditions; the acyl complexes (CO)2(η5-C5H5)FeCOCH2-C(CH3)3 (11), 71%, or (CO)2(η5-C5H5)FeCO(1-norbornylcarbinyl) (14), 80%, respectively, are the only organometallic products.

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