Catalytic activation of diazo compounds using electron-rich, defined iron complexes for carbene-transfer reactions

Non-decarbonylative photochemical versus thermal activation of Bu4N[Fe(CO)3(NO)] - the Fe-catalyzed Cloke-Wilson rearrangement of vinyl and arylcyclopropanes

The base metal complex Bu4N[Fe(CO)3(NO)] (TBA[Fe]) catalyzes the rearrangement of vinyl and arylcyclopropanes both under thermal or photochemical conditions to give the corresponding vinyl or aryldihydrofurans in good to excellent yields. Under photochemical conditions the reaction is performed at room temperature. Spectroscopic investigations show that the metal carbonyl catalyst is not decarbonylated. The best performance was observed at a wavelength of 415 nm. icMRCI+Q analysis of the excited singlet and triplet states of the [Fe(CO)3(NO)] anion was performed and used to calculate the vertical excitation energies which are in good agreement with the experimental data. CASSCF analysis indicates that the Fe center in all excited states of the ferrate becomes more electrophilic while adopting a distorted tetrahedral configuration. Both aspects have a positive synergistic effect on the formation of the initial π-complex with the incoming organic substrate.

Iron-catalyzed transformations of diazo compounds

Although iron-promoted diazo transformations were only discovered during the 1990s, iron can undergo facile changes in its oxidation state and possesses distinct Lewis acid character, and these properties have afforded iron a privileged position as a catalyst in the transformations of diazo compounds. In this review, we have provided an overview of the iron-catalyzed diazo transformation reactions reported in the literature by the end of 2013 with the aim of stimulating further interest in this area of research.

Fe or Fe-NO catalysis? A quantum chemical investigation of the [Fe(CO)3(NO)](-)-catalyzed Cloke-Wilson rearrangement

A quantum chemical investigation of the Bu4N[Fe(CO)3(NO)]-catalyzed Cloke-Wilson rearrangement of vinyl cyclopropanes is reported. It was found that allylic C-C bond activation can proceed through a SN2' or SN2-type mechanism. The application of the recently reported intrinsic bond orbital (IBO) method for all structures indicated that one Fe-N π bond is directly involved. Further analysis showed that during the reaction oxidation occurs at the NO ligand exclusively.

Synthesis, electronic structure and reactivity of bis(imino)pyridine iron carbene complexes: evidence for a carbene radical

The reactivity of the disubstituted diazoalkane, N₂CPh₂ with a family of bis(imino)pyridine iron dinitrogen complexes was examined.

A gold-catalysed fully intermolecular oxidation and sulfur-ylide formation sequence on ynamides

A chemoselective three-component oxidation-intermolecular sulfur ylide formation-rearrangement sequence provides efficient access to functionalised tertiary thioethers from ynamides.