131565-26-9

Upstream product

• 186581-53-3 diazomethane 
• 14367-04-5 erythro-2-Ethyl-3-hydroxy-3-phenylpropionsaeure 
• 3196-15-4 Methyl 2-bromobutyrate 
• 100-52-7 benzaldehyde 
• 55453-12-8 (1-methoxybut-1-enyloxy)trimethylsilane 
• 623-43-8 methyl crotonate 
• 14367-04-5 threo-2-Ethyl-3-hydroxy-3-phenylpropionsaeure 
• 5336-76-5 methyl 2-benzoylbutanoate 
• 79868-63-6 2-(α-hydroxy-benzyl)-butyric acid methyl ester 
• 623-42-7 butanoic acid methyl ester 
• 4637-24-5 N,N-dimethyl-formamide dimethyl acetal 

Relevant academic research and scientific papers

Chiral ferrocene P-N-N ligand with high steric hindrance, and preparation method and application thereof

The invention provides a chiral ferrocene P-N-N ligand compound with high steric hindrance, and a preparation method and application thereof, specifically application of the chiral ferrocene P-N-N ligand compound to asymmetric catalytic hydrogenation of beta-keto ester compounds. The preparation method for the chiral ferrocene P-N-N ligand compound with high steric hindrance comprises the following steps: dissolving a chiral ferrocenephosphine-amine compound and a pyridone compound in a reaction solvent; adding active Al2O3 and a dehydrating agent; carrying out a reflux condensation reaction; then carrying out re-dissolving in absolute ethyl alcohol after filtering and desolventizing; adding a palladium/carbon catalyst and carrying out a hydrogenation reaction in an autoclave under a certain reaction pressure; and then successively carrying out filtration, desolventizing and column chromatographic treatment so as to obtain the desired chiral ferrocene P-N-N ligand compound with high steric hindrance. The chiral ferrocene P-N-N ligand compound with high steric hindrance in the invention can be used for asymmetric catalytic hydrogenation of beta-keto ester and can realize high-yield, high-diastereoselectivity high-enantioselectivity preparation of chiral beta-hydroxy ester.

Sterically Hindered Chiral Ferrocenyl P,N,N-Ligands for Highly Diastereo-/Enantioselective Ir-Catalyzed Hydrogenation of α-Alkyl-β-ketoesters via Dynamic Kinetic Resolution

A new class of sterically hindered chiral ferrocenyl P,N,N-ligands have been prepared through a two-step transformation from (Sc,Rp)-PPFNH2, in which a new (R)-stereogenic center at the pyridinylmethyl position was generated in high diastereoselectivity. With these newly developed P,N,N-ligands, Ir-catalyzed asymmetric hydrogenation of various α-alkyl-substituted β-aryl-β-ketoesters via dynamic kinetic resolution has been realized in high diastereo- and enantioselectivities for the first time, which led to a variety of optically active anti-β-hydroxyesters in up to 99% ee. The study indicated that the additional stereocenter at the pyridinylmethyl position of these ligands is crucial to realize this hydrogenation.

Reductive aldol-type reaction of α,β-unsaturated esters with aldehydes or ketones in the presence of Rh catalyst and Et2Zn

The reaction of RhCl(PPh3)3 with Et2Zn easily generated a rhodium-hydride complex (Rh-H) that added to α,β-unsaturated esters to form rhodium enolate complexes by formal 1,4-reduction. These rhodium enolates gave the corre

Surface-mediated solid phase reaction. Part 9. A convenient procedure for aldol reaction of ketene silyl acetals with aldehydes on the solid surface of alumina

The aldol reaction of ketene silyl acetals with aldehydes proceeds efficiently on the solid surface of alumina impregnated with anhydrous zinc chloride under sonication providing aldol products in high yields and with good stereoselectivity.

Stereoselective reduction of 2-methyl-3-oxo esters (or amides) with sodium borohydride catalyzed by manganese (II) chloride or tetrabutylammonium borohydride. A practical preparation of erythro and threo-3-hydroxy-2-methyl esters (or amides)

erythro-3-Hydroxy-2-methylpropionates or erythro-3-hydroxy-2-methylpropionamides were prepared with high stereoselectivity by NaBH4 reduction of the corresponding 2-methyl-3-oxo esters or 2-methyl-3-oxo amides in the presence of a catalytic amount of manganese(II) chloride. On the other hand, reduction of these substrates with n-Bu4NBH4 provided threo-isomers selectively. erythro-Selective reduction of 2-methyl-3-oxo amides with NaBH3CN in 1N HCl-MeOH is also described.

Design of α-Alkyl β-Hydroxy Esters Suitable for Providing Optical Resolution by Lipase Hydrolysis

A study of the lipase-catalyzed hydrolyses of various α-substituted β-acetoxy esters revealed that a sulfur functional group in the ester, which could play an important role in the stereorecognition by lipase A6 (Aspergillus sp.) and an anti conformation

Dehydrative Decarboxylation of 2,3-Disubstituted 3-Hydroxycarboxylic Acids with Dimethylformamide Acetals - Mechanistic Studies and Preparative Applicability

Dimethylformamide dimethylacetal (2a) converts the threo-3-hydroxycarboxylic acids 4 smoothly into the (E)/(Z)-olefins 7/6 only if R2 is an aryl or vinyl substituent.Althougt the reaction exhibits a distinct (E)-selectivity it cannot be considered as a stereo-controlled olefin synthesis.If R2 is alkyl, 2a generates the methyl esters 10 from 4.The erythro-acids 5 react with 2a to give 43 - 95percent of >98percent sterically pure 7.As the key tranformation on the multistep way from 4/5 to 6/7 the fragmentation of the zwitterionic intermediate 11/20 is postulated.

MONOFLUORINATION STEREOSELECTIVE PAR LE PHENYLTETRAFLUOROPHOSPHORANE (PhPF4) PART. II. APPLICATION A LA SYNTHESE DES ISOMERES threo ET erythro DES ALKYL-2 FLUORO PHENYLPROPANOATES DE METHYLE. ANALYSE CONFORMATIONNELLE PAR R.M.N. DE 19F et 1H

The stereoselective fluorination of four couples of diastereoisomeric 2-alkyl 3-hydroxy 3-phenylpropanoic methyl esters by the reaction of the phenyltetrafluorophosphorane with the corresponding trimethylsilylethers derivatives 2a-h, Tab.IV

STEREOSELECTIVE REDUCTION OF β-KETO ESTERS WITH ZINC BOROHYDRIDE. STEROSELECTIVE SYNTHESIS OF ERYTHRO-3-HYDROXY-2-ALKYLPROPIONATES

Erythro-3-hydroxy-2-alkylpropionates were prepared in high stereoselectivity and in high isolated yield by zinc borohydride reduction of the corresponding β-keto esters.