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[Display omitted] • In situ spectroscopic study of hydroformylation catalysts at typical reaction concentrations. • Two ligands in the literature found to not coordinate to rhodium in the presence of syngas. • The highly active Rh/1,3,5,7-Tetramethyl-6-phenyl-2,4,8-trioxa-6-phosphaadamantane catalyst system studied by in situ HPIR spectroscopy and found to be mixture of resting states, with the composition tuneable by reaction conditions. The paper describes the composition of the resting states of several catalysts for alkene hydroformylation derived from bulky monophosphorus ligands. The results presented assess how bulky ligands compete with CO for the rhodium, and hence the role of 'unmodified' catalysts in alkene hydroformylation in the presence of these ligands. High Pressure Infra-Red (HPIR) spectroscopy was carried out at the rhodium and syngas concentrations typically used during catalysis experiments. These HPIR studies revealed that two ligands previously studied in Rh-catalysed hydroformylation react with [Rh(acac)(CO) 2 ] and H 2 /CO to give the unmodified rhodium cluster, [Rh 6 (CO) 16 ], as the only detectable species. Both less bulky phosphoramidites, and 1,3,5,7-Tetramethyl-6-phenyl-2,4,8-trioxa-6-phosphaadamantane, on the other hand, do not show the presence of [Rh 6 (CO) 16 ], and hence catalysis proceeds by purely ligand modified species under normal conditions. In the case of the Rh/phosphaadamantane catalysts, anecdotal evidence that this only forms a particularly useful catalyst above a certain pressure threshold can be understood in terms of how the catalyst composition varies with pressure. The ligands discussed have all been assessed in the hydroformylation of propene to separate their innate branched selectivity from their ability to isomerise higher alkenes to internal isomers. [ABSTRACT FROM AUTHOR]

An asymmetric hydrogenation of enamines is efficiently catalysed by rhodium complexed with a fluorinated version of the planar chiral paracyclophane-diphosphine ligand, Phanephos. This catalyst was shown to be very active, with examples operating at just 0.1 mol% of catalyst. This catalyst was then successfully adapted to Direct Asymmetric Reductive Amination, leading to the formation of several tertiary amines with moderate ee , if activated ketone/amine partners are used. To create your abstract, type over the instructions in the template box below. Fonts or abstract dimensions should not be changed or altered. Image 1 [ABSTRACT FROM AUTHOR]