- High iso Aldehyde Selectivity in the Hydroformylation of Short-Chain Alkenes
-
The hydroformylation of propene to give predominantly iso-butanal has been achieved; class-leading selectivity is possible even at higher temperatures that deliver fast conversion. Racemic rhodium complexes of bidentate phospholane phosphites derived from tropos-biphenols and unusual solvent systems are the key to the selectivity observed.
- Iu, Leo,Fuentes, José A.,Janka, Mesfin E.,Fontenot, Kevin J.,Clarke, Matthew L.
-
supporting information
p. 2120 - 2124
(2019/01/25)
-
- Solvent-free asymmetric olefin hydroformylation catalyzed by highly cross-linked polystyrene-supported (R,S)-BINAPHOS-Rh(I) complex
-
Using an (R,S)-BINAPHOS-Rh(I) catalyst that is covalently anchored to a highly cross-linked polystyrene support, asymmetric hydroformylation of olefins was performed in the absence of organic solvents. The reaction of cis-2-butene, a gaseous substrate, provided (S)-2-methylbutanal with 100% regioselectivity and 82% ee upon treatment with H2 (12 atm) and CO (12 atm) in a batchwise reactor equipped with a fixed bed. The polymer-supported catalyst was applicable to a continuous vapor-flow column reactor, and thus, 3,3,3-trifluoropropene was converted into (S)-2-trifluoromethylpropanal with an iso/normal ratio of 95/5 and 90% ee. Less volatile olefins, such as styrene, vinyl acetate, 1-alkenes, and fluorinated alkenes, were successfully converted into the corresponding isoaldehydes with high ee values, when they were injected through a supercritical CO2-flow column reactor. Successive injection of a series of olefins realized the conversion of an olefin library into an optically active aldehyde library.
- Shibahara, Fumitoshi,Nozaki, Kyoko,Hiyama, Tamejiro
-
p. 8555 - 8560
(2007/10/03)
-
- Synthesis of New Chiral Phosphinephosphites Having 2-Diphenylphosphinobiphenyl-2'-yl Backbone and Their Use in Rh(I)-Catalyzed Asymmetric Hydroformylations
-
New chiral phosphinephosphites (R)-(5,5'-dichloro-2-diphenylphosphino-4,4',6,6'-tetramethylbiphenyl-2'-yl)(S)-1,1'-binaphthalen-2,2'-diyl)phosphite and its enantiomer (S,R)-BIPHEMPHOS have been synthesized from 5,5'-dichloro-4,4',6,6'-tetramethyl-2,2'-biphenyldiol in enantiomerically pure form.Their Rh(I) complexes have been shown to be highly efficient catalysts for asymmetric hydroformylations of a variety of olefinic substrates.The corresponding phosphinephosphites derived from 2,2'-biphenyldiol were also tested as ligands for asymmetric hydroformylation.
- Higashizima, Takanori,Sakai, Nozomu,Nozaki, Kyoko,Takaya, Hidemasa
-
p. 2023 - 2026
(2007/10/02)
-
- Asymmetric Hydroformylation of 1,2-Disubstituted Olefins Catalysed by Chiral Phosphinephosphite-Rhodium(I) Complexes
-
Hydroformylations of internal olefins such as (E)- and (Z)-but-2-ene, (E)- and (Z)-1-phenylprop-1-ene, indene, and 1,2-dihydronaphthalene catalysed by (R,S)-binaphos-RhI complex phosphite> or its enantiomer gave the corresponding oxoaldehydes in up to 97percent enantiomeric excess, e.e.
- Sakai, Nozomu,Nozaki, Kyoko,Takaya, Hidemasa
-
p. 395 - 396
(2007/10/02)
-
- TOTAL SYNTHESIS OF (-)-BETAENONE C
-
Stereoselctive synthesis of (-)-betaenone C through intramolecular Diels-Alder reaction has made possible to provide pertinent intermediates for the biosynthetic study of betaenones.
- Ichihara, Akitami,Miki, Shokyo,Kawagishi, Hirokazu,Sakamura, Sadao
-
p. 4551 - 4554
(2007/10/02)
-