159759-69-0Relevant academic research and scientific papers
Asymmetric Hydroformylation Catalyzed by Homogeneous and Polymer-Supported Platinum Complexes Containing Chiral Phosphine Ligands
Parrinello, Giovanni,Stille, J. K.
, p. 7122 - 7127 (1987)
A complex of Pt(II) containing the chiral ligand (2S,4S)-N-(tert-butoxycarbonyl)-4-(diphenylphosphino)-2-pirrolidine in the presence of stannous chloride catalyzed the hydroformylation of a variety of prochiral olefins.Although the branched/normal (b/n) ratios were low (ca. 0.5), high ee's were achieved in the hydroformylation of styrene (70-80percent), p-isobutylstyrene (80percent), 2-vinylnaphthalene (77percent), 2-ethenyl-6-methoxynaphthalene (81percent), 4-(2-thienylcarbonyl)styrene (78percent), vinyl acetate(82percent), N-vinylphthalimide (73percent), methyl methacrylate (60percent), and norbornene (60percent).When the hydroformylation of styrene, 2-ethenyl-6-methoxynaphthalene, and vinyl acetate with PtCl2/SnCl2 was carried out in the presence of triethyl orthoformate, enantiomerically pure acetals were obtained.The hydroformylation in the presence of ethyl orthoformate also could be carried out by using a catalyst containing the PtCl2/SnCl2 complex bound to 60-μm beads composed of cross-linked polystyrene.
Highly enantioselective hydroformylation of aryl alkenes with diazaphospholane ligands
Watkins, Avery L.,Hashiguchi, Brian G.,Landis, Clark R.
scheme or table, p. 4553 - 4556 (2009/05/13)
(Chemical Equation Presented) Asymmetric, rhodium-catalyzed hydroformylation of terminal and internal aryl alkenes with diazaphospholane ligands is reported. Under partially optimized reaction conditions, high enantioselectivity (>90% ee) and regioselectivities (up to 65:1 α:β) are obtained for most substrates. For terminal alkenes, both enantioselectivity and regioselectivity are proportional to the carbon monoxide partial pressure, but independent of hydrogen pressure. Hydroformylation of para-substituted styrene derivatives gives the highest regioselectivity for substrates bearing electron-withdrawing substituents. A Hammett analysis produces a positive linear correlation for regioselectivity.
Electronic effects in asymmetric catalysis: Hydroformylation of olefins
RajanBabu,Ayers, Timothy A.
, p. 4295 - 4298 (2007/10/02)
Highly tunable carbohydrate vicinal diphosphinites are viable ligands for the Rh-catalyzed hydroformylation of olefins. Substitution of electron-withdrawing aryl groups at phosphorus in these diphosphinites increases the enantioselectivity of the hydroformylation process. Very high branched to linear ratios of product aldehydes (> 94%) were obtained. Thus far only moderate enantioselectivity (up to 72%) has been achieved.
