0000000000266349
AUTHOR
And Mercedes Sanaú
Enantio- and Diastereocontrol in Intermolecular Cyclopropanation Reaction of Styrene Catalyzed by Dirhodium(II) Complexes with Bulky ortho-Metalated Aryl Phosphines: Catalysis in Water as Solvent. Study of a (+)-Nonlinear Effect
Enantiomerically pure dirhodium(II) complexes with ortho-metalated para-substituted aryl phosphines have been shown to lead to an enantio- and diastereoselective cyclopropanation of styrene with ethyl diazoacetate. Enantioselectivities up to 91% and diastereoselectivities up to 90% are observed for ethyl cis-2-phenylcyclopropanecarboxylate. High enantio- and diastereoselectivities are observed for the synthesis of ethyl cis-2-phenylcyclopropanecarboxylate using water as solvent. Additionally, a (+)-nonlinear effect, (+)-NLE, has been observed and studied in the asymmetric catalytic reaction developed in n-pentane.
Ruthenium Janus-Head Complexes with a Triazolediylidene Ligand. Structural Features and Catalytic Applications
The use of the ligand triazolediylidene (ditz), has afforded the preparation of two new complexes of Ru in which the ligand is bridging two metal fragments in a facially opposed (Janus-head) disposition. One of the complexes is dinuclear (2) and the other tetranuclear (3). The tetranuclear compound displays interesting structural features, as shown by the X-ray diffraction studies. The two complexes have been tested in the catalytic β-alkylation of secondary alcohols with primary alcohols, providing high activities when both aliphatic and aromatic alcohols are used.
“Cp*Ir(III)” Complexes with Hemicleaveable Ligands of the Type N-Alkenyl Imidazolin-2-ylidene. Reactivity and Catalytic Properties
A series of Cp*Ir(III) complexes with N-alkenyl imidazole-2-ylidene ligands have been obtained by transmetalation of the previously obtained silver−carbene species. Two structural and electronic pa...