Mechanistic aspects of hydrogen addition during enantioselective rhodium-catalysed reduction of CC double bonds with formic acid/triethylamine or molecular hydrogenBased on the presentation given at Dalton Discussion No. 4, 10–13th January 2002, Kloster Banz, Germany.

Reactivity of rhodium-β-diketonato cyclooctadiene derivatives with mono- and di-phosphines. Synthesis, structural and spectroscopic characterization of Rh(I) and Rh(III) species containing unsymmetrical β-diketonate and P-donor ligands

“…As previously for derivatives 1Á/4, also the formation of 5 in C 6 D 6 has been followed by 31 P-NMR: together with resonances due to 5, two minor resonances appear as doublets at 10.4 ppm ( 1 J Rh Á P 0/137 Hz) and at 8.6 ppm ( 1 J Rh Á P 0/131 Hz), likely due to [Rh(dppp) 2 ](Q O ) and [Rh(dppp)(1,5-cod)](Q O ) species, respectively (Scheme 4). After addition of O 2 all disappear and a doublet at 26.1 ( 1 J Rh Á P 0/138 Hz) emerges, likely due to a Rh(III) species as [Rh(dppp) 2 (O 2 )](Q O ) [3,24,27]. This species has been also detected in CD 3 CN by ESI-MS spectroscopy.…”

“…31 P-NMR shows two double doublets with 1 J Rh Á P of ca. 185 Hz, typical for [Rh(b-diketonate)(P 2 -donor)] species [3,27]. 5 has been recrystallised by anhydrous benzene and the solvate [Rh(Q O )(dppp)]×/ C 6 H 6 has been investigated by X-ray crystallography.…”

Amino‐phosphanes in RhI‐Catalyzed Hydroformylation: New Mechanistic Insights Using D2O as Deuterium‐Labeling Agent

“…The relative amounts of the various products were quantified by integration of the 13 C{ 1 H} resonances affected by the secondary isotope shift, since the Overhauser effect does not depend on the substitution pattern at the adjacent C atom. [32][33][34] Thus, for instance, the relative proportion of compounds PhCH(CH 3 )CHO and PhCH(CH 2 D)CHO were obtained by integration of the two proton-decoupled methyne signals, whereas the relative proportions of compounds PhCH(CH 3 )CHO and PhCD(CH 3 )CHO were obtained by integration of the two proton-decoupled methyl signals. Figure 2 shows the 13 C NMR spectra for three representative product mixtures.…”

Supercritical and Compressed Carbon Dioxide as Reaction Medium and Mass Separating Agent for Hydrogenation Reactions using Organometallic Catalysts

“…In particular, the 2,3-and 1,3-pattern in the dideutero products 17-d 2 differs significantly from the classical hydrogenation and the transfer hydrogenation pathway owing to a shift in relative rates between rearrangement and hydrogen transfer processes [51]. In particular, the 2,3-and 1,3-pattern in the dideutero products 17-d 2 differs significantly from the classical hydrogenation and the transfer hydrogenation pathway owing to a shift in relative rates between rearrangement and hydrogen transfer processes [51].…”