SYNTHESIS OF HALF-SANDWICH IRON CARBOXYALKYLS AND IRON (THIOCARBOXY)ALKYLS - REACTION OF CYCLOPENTADIENYLDICARBONYLIODOIRON WITH O- AND S-BASED NUCLEOPHILES IN THE PRESENCE OF TRIPHENYLPHOSPHINE

摘要

One equivalent of NaOMe is added to an equimolar mixture of(eta(5)-C5H5)Fe(CO)(2)I (1) and PPh(3) after the addition of a few drops of n-BuLi, to take advantage of the catalytic formation of [(eta(5)-C5H5)Fe(CO)(2)(PPh)(3)]I-+(-) (3), which, upon formation, becomes the virtual reactant with OMe(-). The OMe(-) reaction yields the methyl carboxylate (eta(5)-C5H5)Fe(CO)(PPh)(3)C(O)OMe (8Me). A similar pattern is observed in the OPh(-), SMe(-), and SPh(-) reactions, resulting in the derivatives (eta(5)-C5H5)Fe(Co)(PPh)(3)C(O)OPh (8Ph), (eta(5)-C5H5)Fe(Co)(PPh)(3)C(O)SMe (9Me), and (eta(5)-C5H5)Fe(Co)(PPh)(3)C(O)SPh (9Ph), respectively. The metalloesters exist simultaneously in the molecular form (8R) and the ionic form [(eta(5)-C5H5)Fe(Co)(2)(PPh)(3)](+) OR(-) (10R; R = Me, Ph) in solutions of medium polarity (CHCl3 CH2Cl2 and MeCN), whereas the S analogs exist only in the ionic form. In CHCl3, CH2Cl2, and MeCN solutions, the ratio of neutral 8Me to ionic 10Me is ca. (6.0-8.4):1, as judged from the NMR measurements. Nonetheless, the ratio of neutral 8Ph to ionic 10Ph is ca. (0.17-0.25):1. [References: 36]