19128-85-9

Upstream product

• 13794-14-4 2-phenoxybutyric acid 
• 937025-54-2 (Z)-α-phenoxybutenoic acid 
• 591-50-4 iodobenzene 
• 3347-90-8 (2S)-2-hydroxybutanoic acid 
• 90843-51-9 α-phenoxy-2-butenoic acid 
• 108-95-2 phenol 

Relevant academic research and scientific papers

OXA-SPIRODIPHOSPHINE LIGAND AND METHOD FOR ASYMMETRIC HYDROGENATION OF alpha, beta-UNSATURATED CARBOXYLIC ACIDS

The present invention provides an oxa-spirodiphosphine ligand having a structure of general Formula (I) below: wherein in general Formula (I), R1, R2, R3 and R4 are the same, and are alkyl, alkoxy, aryl, aryloxy

para-Selective arylation and alkenylation of monosubstituted arenes using thianthreneS-oxide as a transient mediator

Using thianthreneS-oxide (TTSO) as a transient mediator,para-arylation and alkenylation of mono-substituted arenes have been demonstratedviaapara-selective thianthrenation/Pd-catalyzed thio-Suzuki-Miyaura coupling sequence under mild conditions. This reaction features a broad substrate scope, and functional group and heterocycle tolerance. The versatility of this approach was further demonstrated by late-stage functionalization of complex bioactive scaffolds, and direct synthesis of some pharmaceuticals, including Tetriprofen, Ibuprofen, Bifonazole, and LJ570.

Oxa-spiral diphosphine ligand and application thereof in alpha, beta-unsaturated carboxylic acid asymmetric hydrogenation

The invention provides an oxa-spiral diphosphine ligand. The oxa-spiral diphosphine ligand has a structure shown by a general formula (I) as shown in description, wherein R1, R2, R3 and R4 in the general formula (I) are same and are alkyl, alkoxy, aryl, aroxyl, or hydrogen atoms; R1, R2, R3 and R4 comprise forms of ring formation, non-ring formation, any two ring formation or multiple-ring formation between pairs; R5 and R6 are alkyl, aryl or hydrogen atoms; and R7 and R8 are alkyl or benzyl or aryl. The invention further provides application of the oxa-spiral diphosphine ligand O-SDP in the alpha, beta-unsaturated carboxylic acid asymmetric hydrogenation. A complex of the oxa-spiral diphosphine ligand O-SDP and ruthenium has excellent activity and enantioselectivity in the asymmetric hydrogenation of the alpha, beta-unsaturated carboxylic acid in multiple types, and a chiral carboxylic acid product is obtained with the enantioselectivity being up to 99%. The synthesis method can be applied to the construction of a core skeleton of chemical molecules with important activity, wherein the chemical molecules comprise Paroxetine, Femoxetine, nipecotic acid and Sacubitril.

Enantioselective hydrogenation of α-aryloxy and α-alkoxy α,β-unsaturated carboxylic acids catalyzed by chiral spiro iridium/phosphino-oxazoline complexes

The iridium-catalyzed highly enantioselective hydrogenation of α-aryloxy and α-alkoxy-substituted α,β-unsaturated carboxylic acids was developed. By using chiral spiro phosphino-oxazoline ligands, the hydrogenation proceeded smoothly to produce various α-aryloxy- and α-alkoxy-substituted carboxylic acids with extremely high enantioselectivities (ee up to 99.8%) and reactivities (TON up to 10 000) under mild conditions. The hydrogenation of R-benzyloxy-substituted α,β-unsaturated acids provided an efficient alternative for the synthesis of chiral R-hydroxy acids after an easy deprotection. A mechanism involving a catalytic cycle between IrI and IrIII was proposed on the basis of the coordination model of the unsaturated acids with the iridium metal center. The rationality of the catalytic cycle, with an olefin dihydride complex as the key intermediate, was supported by the deuterium-labeling studies. The X-ray diffraction analysis of the single crystal of catalyst revealed that the rigid and sterically hindered chiral environment created by the spiro phosphino-oxazoline ligands is the essential factor that permits the catalyst to obtain excellent chiral discrimination. A chiral induction model was suggested on the basis of the catalyst structure and the product configuration.

Asymmetric hydrogenation of α,β-unsaturated carboxylic acids catalyzed by ruthenium(II) complexes of spirobifluorene diphosphine (SFDP) ligands

The ruthenium diacetate complexes ligated by chiral spirobifluorene diphosphines (SFDP) were very effective catalysts for the asymmetric hydrogenation of tiglic acid derivatives and α-methylcinnamic acid derivatives with high activities and excellent enantioselectivities (up to 98% ee). The α-aryloxybutenoic acids can also be hydrogenated by these catalysts to provide the corresponding saturated α-aryloxybutanoic acids in high yields (89-93%) and enantioselectivities (up to 95% ee). In this reaction, the SFDP ligand with para-methyl groups on the P-phenyl rings gave the best results.

Enantioselective hydrogenation of α-aryloxy α,β- unsaturated acids. Asymmetric synthesis of α-aryloxycarboxylic acids

(Chemical Equation Presented) A facile preparation of chiral α-aryloxy carboxylic acids via asymmetric hydrogenation of the corresponding unsaturated acids has been discovered. A number of catalysts have been identified that give high product enantioselectivity, and the scope of the reaction has been examined with respect to substitution on the aromatic ring and olefin.

Enzymatic enantioselective ester hydrolysis by carboxylesterase NP

The enzymatic hydrolysis of a series of carboxylic esters by carboxylesterase NP has been investigated in order to determine the scope and limitations of this enzyme. 2-Substituted propionates were hydrolyzed with high enantioselectivity when an aromatic moiety was part of the 2-substituent.Enantioselective hydrolysis could be accomplished with several 2-arypropionates, 2-(aryloxy)propionates and N-arylalanine esters.The propionate esters yielded propionic acids as (S) enantiomers, whereas the alanine esters yielded the (R) enantiomers.Without a 2-aryl substituent, the enzymatic hydrolysis of the propionates occurred at a lower rate without acceptable enantioselectivity.In addition to 2-substituted propionates, only a few other esters were hydrolyzed with high enantioselectivity by carboxylesterase NP, such as some prochiral disubstituted malonates. 1-Phenylethylacetate was the only substrate with chirality in the alcohol part of the ester that was found to be hydrolyzed enantioselectively.Carboxylesterase NP proved to be a powerful enzyme for kinetic resolution of propionate esters with an aromatic ring containing a 2-substituent.