Theory Rules Out a [2 + 2] Addition of Osmium Tetroxide to Olefins as Initial Step of the Dihydroxylation Reaction
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Johnson R. A., 1993, Catalytic Asymmetric Synthesis, 227
Jacobsen E. N., 1988, J. Am. Chem. Soc., 110
Griffith W. P., 1980, Gmelin Handbuch der Anorganischen Chemie, Osmium Suppl., 184
(b)D. V.McGrath A.Makita K. B.Sharpless in preparation. We thank Prof. Sharpless for a preprint.
The program packages Gaussian 94 [17a] and ACESII [17b] have been used for the calculations. The geometries were optimized at the DFT level with the nonlocal hybrid functionals B3LYP of Becke [18]. A quasi‐relativistic effective core potential (ECP) [8] for osmium (small core) with a (441/2111/21) basis set for the 16 valence and outer‐core electrons in conjunction with a 6–31 G(d) basis set for the other atoms was used. This is our standard basis set II [19]. The vibrational frequencies and the intrinsic reaction coordinates [14] were calculated at the same level of theory (B3LYP/II). Improved total energies of the base‐free species were calculated at the CCSD(T) level [9] with the same basis set II. except that for computational reasons an STO‐3G basis set was employed for hydrogen. The accuracy of the CCSD(T) level of theory for calculating energies of transition metal compounds has been documented [19]. CCSD(T) calculations of the NH3‐complexed species could not be carried out for technical reasons (<2GByte size limit for a single file). The accuracy of B3LYP calculations is also well known [20].
Similar results have been obtained in an independent theoretical study by Morokuma and co‐workers. We thank Prof. Morokuma for sending us a preprint of his work:S.Dapprich G.Ujaque F.Maseras A.Lledós K.Morokuma J. Am. Chem. Soc. in press.
Frisch M. J., 1995, Gaussian 94
Stanton J. F., 1991, ACES II, an ab initio program system
(b)D.Heller(Rostock) personal communication to G. F.