123135-89-7

Upstream product

• 37002-45-2 (4S,5S)-2,2-dimethyl-4,5-bis(p-toluenesulfonyloxymethyl)-1,3-dioxolan 
• 65567-06-8 lithium diphenylphosphide 
• 829-85-6 diphenylphosphane 
• 69055-79-4 (+)-(2R,3R)-2,3-O-isopropylidene-2,3-dihydroxy-1,4-dichlorobutane 
• 93834-41-4 (-)-2,3-O-isopropylidene-4-diphenylphosphino-1-O-tosyl-1,2,3-butanetriol 
• 123135-91-1 C₁₆H₂₀N₂P^(1-)*Li⁽¹⁺⁾ 
• 1769-51-3 bis-(4-dimethylaminophenyl)phosphine 
• 124550-71-6 (4R,5R)-4-chloromethyl-5-diphenylphosphinomethyl-2,2-dimethyl-1,3-dioxolan 

Relevant academic research and scientific papers

Synthesis of efficient chiral bisphosphine ligands, modified DIOPs, (4R,5R)-4-(Diaryl- or dialkylphosphino)methyl-5-(diarylphosphino)methyl-2,2- dimethyl-1,3-dioxolanes, and their use in rhodium(I)-catalyzed asymmetric hydrogenations

Modified DIOPs, (4R,5R)-4-(diaryl- or dialkyphosphino)methyl-5- (diarylphosphino)methyl-2,2-dimethyl-1,3-dioxolanes, were prepared on the basis of our design concept, and used as ligands for the rhodium(I)-catalyzed asymmetric hydrogenations of ketopantolactone, itaconic acid, dimethyl itaconate, and β-aryl-substituted itaconic acid derivatives. A neutral rhodium(I)-complex of (4R-trans)-dicyclohexyl[[5- [(diphenylphosphino)methyl]-2,2-dimethyl-1,3-dioxolan-4-yl]methyl]phosphine (DIOCP) bearing both a dicyclohexylphosphino group and a diphenylphosphino group was found to be a more efficient catalyst than the original DIOP in the asymmetric hydrogenation of ketopantolactone. Modified DIOPs bearing electron-donating groups at their para positions were efficient ligands for the rhodium(I)-catalyzed assymetric hydrogenations of itaconic acid and its derivatives; in particular, (4R-trans)-[(2,2-dimethyl-1,3-dioxolane-4,5- diyl)bis(methylene)]bis[bis(4'-methoxy-3',5'-dimethylphenyl)phosphine] (MOD- DIOP) bearing both a p-methoxy group and two m,m'-methyl groups on each phenyl group showed much higher enantioselectivity and catalytic activity than DIOP.

Asymmetrische katalytische Hydrierung von Acylamino-acrylsaeureethylester und (Z)-Acylamino-zimtsaeuremethylester mit Rhodium-(Diop-Derivat)-Komplexen als Katalysatoren. Einfluss der Einfuehrung zweier Bisarylphosphino-Gruppen mit unterschiedlichen Elektronendichten an den Phosphorato...

(R,R)-Diop was modified by the introduction of two bis-arylphosphino groups of different charge densities on the phosphorus atoms, so that unsymmetrically substituted diop derivatives were formed.The effects of the substituents and the loss of the two-fold rotation axis were examined on the basis of the hydrogenation of ethyl α-acylamino-acrylate (AAEE) and (Z)-methyl α-acylamino-cinnamate (AZME) with +BF4- (ns-Rh) as the catalytic precursor with the least steric influence by the substituents.We reported recently the results of the hydrogenation of the same substrates but with +BF4- (s-Rh) as the catalytic precursor.The electronic and steric effects of the substituents we had found by the hydrogenation experiments with the s-Rh (1) affected the optical yields with the ns-Rh nearly additively.This means that the optical yield obtained with an ns-Rh was fairly consistent with the value calculated by averaging the optical yields of the corresponding s-Rh.Surprisingly the electronic and in special cases the steric features of the substituents are sufficient to explain the results.The loss of the two-fold rotation had no significant effect.The effects of solvation were not examined.

CATALYTIC ASYMMETRIC HYDROGENATION WITH RHODIUM COMPLEXES OF IMPROVED DIOPS BEARING PARA-DIMETHYLAMINO GROUP ON THE BASIS OF OUR DESIGNING CONCEPT

Unsymmetrized and symmetrized DIOP analogues bearing para-dimethylamino group have been synthesized to prove the general utility of our designing concept for developing highly effective catalysts.Their rhodium complexes have been shown to be much more effective in the asymmetric hydrogenations than that of DIOP.