Preparation of Cp-Functionalized N-Heterocyclic Carbene Complexes of Ruthenium. Resolution of Chiral Complexes and Catalytic Studies
摘要:
A series of piano-stool ruthenium(II) complexes bearing bidentate cyclopentadienyl-functionalized N-heterocyclic carbene ligands Ru(Cp-X-NHC)(CO)I [Cp = tetramethylcyclopentadienyl (Cp*) and tetrabenzylcyclopentadienyl (Cp-Bz)] have been prepared by the diastereoselective reaction of the imidazolium Cp-X-NHC proligands with [Ru-3(CO)(12)]. The new complexes have been characterized by spectroscopic techniques and X-ray diffraction methods. The enantiopure complexes have been separated by preparative thin-layer chromatography of the diastereomeric mixtures resulting from the reaction of the Ru(Cp-X-NHC)(CO)I compounds with an auxiliary chiral amine. Ru(Cp*-NHC)(CO)I is an efficient catalyst for the isomerization of allylic alcohols both in water and in THF.
Iron(II) Complexes Bearing Chelating Cyclopentadienyl-N-Heterocyclic Carbene Ligands as Catalysts for Hydrosilylation and Hydrogen Transfer Reactions
作者:V. V. Krishna Mohan Kandepi、João M. S. Cardoso、Eduardo Peris、Beatriz Royo
DOI:10.1021/om100246j
日期:2010.6.28
A series of piano-stooliron(II) complexes bearing bidentate cyclopentadienyl-functionalized N-heterocycliccarbene ligands (Cp-NHC)Fe(CO)I (Cp = substituted and unsubstituted cyclopentadienyl) have been prepared upon reaction with Fe(CO)4I2 and characterized by spectroscopic and crystallographic methods. The 16-electron half-sandwich compound (Cp*-NHC)FeCl (Cp* = η5-C5Me4) has been synthesized by