THE STOICHIOMETRIC HYDROGENATION OF 9-METHYLIDENEFLUORENE AND RELATED COMPOUNDS WITH HYDRIDOCOBALT TETRACARBONYL

Article abstract of DOI:10.1016/S0022-328X(00)83858-9

9-Methylidenefluorene (IIa) reacts rapidly with HCo(CO)4 at -67 deg C to give a quantitative yield of 9-methylfluorene (IIIa); k₂=(13.4 +/- 0.5)*10^-2 l mol^-1 s^-1.Although the internal olefin, 9-ethylidenefluorene (IIb) reacts more slowly than IIa, it is hydrogenated about 2.5 times as fast as the terminal olefin, 1,1-diphenylethylene (I).Measurement of the rate of the reaction of IIb with DCo(CO)4 and comparison with HCo(CO)4 shows a very large inverse isotope effect k_H/k_D of 0.43.