39850-66-3Relevant academic research and scientific papers
Support Functionalization with a Phosphine-Containing Hyperbranched Polymer: A Strategy to Enhance Phosphine Grafting and Metal Loading in a Hydroformylation Catalyst
Garcia, Marco A. S.,Heyder, Rodrigo S.,Oliveira, Kelley C. B.,Costa, Jean C. S.,Corio, Paola,Gusevskaya, Elena V.,dos Santos, Eduardo N.,Bazito, Reinaldo C.,Rossi, Liane M.
, p. 1951 - 1960 (2016/07/06)
We present the design of a hydroformylation catalyst through the immobilization of air-stable Rh nanoparticles (NPs) on a magnetic support functionalized with a hyperbranched polymer that bears terminal phosphine groups. The catalyst modification with the hyperbranched polymer improved the metal–support interaction, the metal loading, and the catalytic activity. The catalyst was active for the hydroformylation of natural products, such as estragole, and could be used in successive reactions with negligible metal leaching. The phosphine grafting played a key role in the recyclability of Rh NPs under hydroformylation conditions. The catalytic activity was maintained in successive reactions, even if the catalyst was exposed to air during each recovery procedure. The modification of the support with hyperbranched polyester allowed us either to increase the number of Rh active species or to obtain more active Rh species on the catalyst surface.
Rhodium-catalyzed hydroformylation of olefins: Effect of [bis(2,4-di-tert-butyl) pentaerythritol] diphosphite (alkanox P-24) on the regioselectivity of the reaction
Tijani, Jimoh,El Ali, Bassam
, p. 3492 - 3497 (2008/02/12)
Rhodium (I) associated with [bis(2,4-di-tert-butyl) pentaerythritol] diphosphite (I) as a ligand represents an active catalyst system for highly regioselective hydroformylation of various alkenes. The commercially available bis(2,4-di-tert-butyl)pentaerythritol diphosphite (alkanox P-24) (I), which has been used so far as an antioxidant in the stabilization of polymers, was used as a diphosphite ligand for the selective hydroformylation reaction of olefins. Excellent selectivity towards linear aldehydes and excellent conversions were achieved in the hydroformylation of alkenes. The hydroformylation reaction was applied to various olefinic substrates including the internal alkenes.
Cationic rhodium(I) complexes containing 4,4′-disubstituted 2,2′-bipyridines: A systematic variation on electron density over the metal centre
Ribeiro, Paulo E.A.,Donnici, Claudio L.,Dos Santos, Eduardo N.
, p. 2037 - 2043 (2007/10/03)
A series of [Rh(COD)(X2-bipy)]BF4 complexes (COD = 1,5-cyclooctadiene; X2-bipy = 4,4′-disubstituted 2,2′-bipyridines; X = OCH3, CH3, H, Cl or NO 2) has been prepared from [Rh(COD)Cl]2. The complexes for X = OCH3, Cl and NO2 have not been described previously in the literature. All complexes have been characterised by elemental analysis, IR, 1H NMR and UV-Vis spectrometry. This series of complexes presents a wide variation on electron density over the metal centre with virtually no variation on its steric environment which discloses interesting possibilities for catalytic and electro-catalytic studies. A preliminary evaluation of these complexes on the hydroformylation of camphene and β-pinene showed that under the rather drastic conditions employed the complexes acted as a precursor for [Rh(CO)3H], which accounts for most of the catalytic activity.
Synthesis in the Isocamphane Series, XXVII. Analogues of 4δ-Santalol, I
Buchbauer, Gerhard,Puespoek, Gabriele,Angermayer, Adelheid,Silbernagel, Elisabeth,Manz, Marisa
, p. 387 - 398 (2007/10/02)
The synthesis of 4-(3,3-dimethyl-2-exo-norbornyl)-2-methyl-2-buten-1-ol (5), an analogue of δ-santalol (1) has been described.One route to 5 starts with isocamphenilanyl propionic acid (8) which can be prepared in 4 steps from isocamphenilanic acid (9).Also 4 steps lead from 8 to the target molecule 5 with an overall yield of 24percent.By a second and more convergent route, starting from the very easily obtainable bicyclic ketone 19, the allylic alcohol 5 could be obtained again in 4 steps, but this time with an overall yield of 1.3percent.A new and easy synthesis of isocamphenilanyl acetic acid (15), a potential starting material to 5, has been described, also the preparation of some new isocamphane derivatives. - Keywords: Aldol Reaction; Allylic alcohol; Allylic oxidation; 1,2-bis-(3,3-Dimethyl-2-exo-norbornyl)-ethane; 4-(3,3-Dimethyl-2-exo-norbornyl)-2-methylbut-2-en-1-ol; Isocamphane derivatives; Isocamphenilanyl acetic acid; Odour; Selenium dioxode
