Novel Regio- and Stereoselective Olefin Syntheses: Hydride Abstraction from Organoiron Compounds

Article abstract of DOI:10.1021/jo01290a018

Treatment of the compounds η⁵-C5H5Fe(CO)2CHR¹CH2R² (R=H, alkyl, aryl) with Ph3C⁺BF4^- results in abstraction of a β-hydrogen atom to give triphenylmethane and the cationic olefin complexes, <η⁵-C5H5Fe(CO)2(CHR¹CHR²)>⁺BF4^-; liberation of the olefins can be effected by treatment with sodium iodide in acetone.The reactions have synthetic utility because (a) 1- and 2- alkyliron compounds generally give only the terminal olefin and (b) 3-alkyliron compounds give only (Z)-2-olefins.The thermodynamically more stable E internal olefins are not formed.Optimum reaction conditions and compatibility of various functional groups with the reaction conditions are also discussed.