Demetalation of Tricarbonyl(cyclopentadienone)iron Complexes Initiated by a Ligand Exchange Reaction with NaOH—X-Ray Analysis of a Complex with Nearly Square-Planar Coordinated Sodium
摘要:
A sequential exchange of one carbonyl ligand by a hydrido ligand with NaOH, and then by an iodo ligand with iodopentane and finally treatment with acid transforms tricarbonyl(η4-cyclopentadienone)iron complexes into dicarbonyl(η5-hydroxycyclopentadienyl)iodoiron complexes. These iodo complexes demetalate with high selectivity to the corresponding free ligands on contact with air in daylight. Under basic reaction conditions at the stage of the iodo complex an anionic dicarbonyl(η4-cyclopentadienone)iodoiron complex is generated, which is dimeric in the solid state and has an almost square-planar arrangement of the ligands at the sodium counterion.
(Cyclopentadienone)iron Shvo Complexes: Synthesis and Applications to Hydrogen Transfer Reactions
作者:Tarn C. Johnson、Guy J. Clarkson、Martin Wills
DOI:10.1021/om101101r
日期:2011.4.11
A series of (cyclopendienone)iron tricarbonylcomplexes were prepared using an intramolecular cyclization strategy. These were applied to the catalysis of the oxidation of alcohols to aldehydes and ketones. When paraformaldehyde was used as the hydrogen acceptor, formate esters were obtained as coproducts and, in several cases, the major products.
EnvIRONmentally friendly: The title hydrogenation of aldehydes, ketones, and α,β‐unsaturated aldehydes is reported. In the presence of the catalyst 1, primary, secondary, and allylic alcohols were obtained in good to excellent yields undermild reaction conditions. The catalyst is easily and inexpensively prepared, and is also stable to air, water, and column chromatography.
Control with an iron hand: A broad range of ketimines underwent enantioselectivehydrogenation in the presence of a chiralBrønsted catalyst and a well‐defined nonchiral iron catalyst (see scheme). This procedure constitutes an attractive and environmentally favorable alternative to well‐established asymmetric hydrogenation reactions with precious‐metal catalysts.
Transfer Hydrogenation of Ethyl Levulinate to<i>γ</i>-Valerolactone Catalyzed by Iron Complexes
作者:Nan Dai、Rui Shang、Mingchen Fu、Yao Fu
DOI:10.1002/cjoc.201500035
日期:2015.4
Conversion of biomass‐derived ethyllevulinate to γ‐valerolactone is realized by using homogeneous iron‐catalyzedtransferhydrogenation (CTH). By utilizing Casey's catalyst and cheap isopropanol as hydrogen source, γ‐valerolactone can be generated in 95% yield. Addition of catalytic amount of base is important to achieve good yield.