CpMo(CO)3Cl as a precatalyst for the epoxidation of olefins

Abstract

The tricarbonyl complex CpMo(CO) 3 C1 was found to act as a precatalyst for the reaction of tert-butyl hydroperoxide and olefins to yield the corresponding epoxides and diols. Under the reaction conditions, oxidative decarbonylation leads to the formation of the dioxo complex CpMoO 2 Cl. The catalytic recyclability and the effect of temperature on the catalytic results have been examined, and a reaction mechanism proposed, supported by kinetic modelling.

Immobilisation of η3‐Allyldicarbonyl Complexes of MoII with Bidentate Nitrogen Ligands within Aluminium‐Pillared Clays

“…It has been reported for (cyclopentadienyl)Mo(CO) 3 Cl-type compounds, used as catalyst precursors for cyclooctene epoxidation under similar reaction conditions, that the oxidative decarbonylation (OD) of the complexes with TBHP is necessary for the formation of active oxomolybdenum species. [16,17] A similar mechanistic feature may be involved for the compounds described above, as postulated in our recent work. [9] In general, no induction periods are observed for the carbonyl precursor complexes, suggesting that the OD is relatively fast and does not limit the rate of epoxidation of cyclooctene.…”

Oxidation of [CpMo(CO)3R] olefin epoxidation precatalysts with tert-butylhydroperoxide

“…complexes have been synthesized and applied in situ as precatalysts for epoxidation with hydroperoxide oxidants [20]. Subsequent kinetic and mechanistic work has shown that the dioxo complexes are further oxidized to oxo-peroxo species [CpMo(O)(g 2 -O 2 )R] with TBHP and the latter are also active catalysts in some cases [21][22][23][24][25].…”

Molybdenum(II) catalyst precursors in olefin oxidation reactions

“…MoCp and Mo(L 2 )Br are isolobal [31] (Chart 1). It was a breakthrough to find out that these Mo(VI) complexes could be obtained in situ by addition of TBHP to the Mo(II) [CpMo(CO) 3 X] precursors [32,33] (Chart 1) and used directly. Kinetic experiments gave much insight on the mechanism, [34] which was extensively studied by DFT methods, by some of us, [12,13,35] and other groups.…”