Direct Conversion of Ethyl Ketone to Alkyl Ketone via Chelation-Assisted Rhodium(I)-Catalyzed Carbon–Carbon Bond Cleavage: Ligands Play an Important Role in the Inhibition of β-Hydrogen Elimination

Decarbonylative cycloaddition of 1H-indene-1,2,3-trione and norbornene via rhodium(i)-catalyzed carbon–carbon bond cleavage

2,3-Dihydro-1H-inden-1-one derivatives were synthesized by a [5+2−2] decarbonylative cycloaddition of 1H-indene-1,2,3-trione and norbornene via rhodium(i) catalyzed direct carbon–carbon bond cleavage.

Activation, Deactivation and Reversibility Phenomena in Homogeneous Catalysis: A Showcase based on the Chemistry of Rhodium/Phosphine Catalysts

In the present work, the rich chemistry of rhodium/phosphine complexes, which are applied as homogeneous catalysts to promote a wide range of chemical transformations, has been used to showcase how the in situ generation of precatalysts, the conversion of precatalysts into the actually active species, as well as the reaction of the catalyst itself with other components in the reaction medium (substrates, solvents, additives) can lead to a number of deactivation phenomena and thus impact the efficiency of a catalytic process. Such phenomena may go unnoticed or may be overlooked, thus preventing the full understanding of the catalytic process which is a prerequisite for its optimization. Based on recent findings both from others and the authors’ laboratory concerning the chemistry of rhodium/diphosphine complexes, some guidelines are provided for the optimal generation of the catalytic active species from a suitable rhodium precursor and the diphosphine of interest; for the choice of the best solvent to prevent aggregation of coordinatively unsaturated metal fragments and sequestration of the active metal through too strong metal–solvent interactions; for preventing catalyst poisoning due to irreversible reaction with the product of the catalytic process or impurities present in the substrate.