Electronic effects in asymmetric catalysis: Hydroformylation of olefins

Solvent‐Free Olefin Hydroformylation Using Hemispherical Diphosphites

“…From the literature it is known that hydroformylation of 2-vinylnaphthalene with conventional diphosphanes, mainly results, as for styrene, in the corresponding branched aldehyde. [34,35] Interestingly, we found that with catalysts 3 and 4 the linear aldehyde was the major regioisomer [linear selectivity: 67.9 % (3), 72.0 % (4); see Table 6, entries 1 and 2]. In these runs important amounts of hydrogenated substrate (2-ethylnaphthalene) were also produced.…”

Ligand modified real heterogeneous catalysts for fixed-bed hydroformylation of propylene

“…In spite of the high level of implemented commercial processes, their practical applications have been limited by difficulties in achieving industrially viable catalyst-product separation [3]. A series of studies of this catalyst system led to an understanding of the factors that govern reactivity and selectivity [4]: -donor ligands may inhibit the reaction completely, switching to stronger -acceptor ligands such as phosphites leading to more active and more selective hydroformylation catalysts [5][6][7][8].…”

Synthesis of Pt compounds containing chiral (2S,4S) -pentane-2,4-diyl-bis(5H-dibenzo[b]phosphindole) as ligand and their use in asymmetric hydroformylation of styrene derivatives

“…High enantiomeric excesses in the branched aldehydes can be readily achieved by the use of platinum-tin [5][6][7][8] and rhodium [9][10][11] complexes of various chiral ligands. The transformation of the formed aldehyde products to the desired acids by oxidation is also a simple one-step procedure [12].…”

“…The transformation of the formed aldehyde products to the desired acids by oxidation is also a simple one-step procedure [12]. The recently developed Rh-based asymmetric hydroformylation catalysts, wkich utilize chiral bidentate phosphine-phosphite or diphosphite ligands are generally superior to Pt-Sn systems containing chiral diphosphines in terms of regioselectivity [1,2,[9][10][11]. However, the moderate branched aldehyde selectivity of the latter system can also be improved by using more suitable ligands than the ones containing diphenylphosphino moieties.…”