440084-24-2Relevant academic research and scientific papers
A study on the enzyme catalysed enantioselective hydrolysis of methyl 2-methyl-4-oxopentanoate, a precursor of chiral γ-butyrolactones
Ferreira, Edgard A.,Rodezno, Sindy V. A.,Omori, álvaro T.,Cunha, Rodrigo L. O. R.
, p. 115 - 123 (2018/12/04)
Porcine pancreas lipase (PPL) resolution of the α-methyl group of racemic methyl 2-methyl-4-oxopentanoate, a valuable synthetic precursor of fragrances and marine natural products, was enhanced by salt modulation of the enzymatic hydrolysis. For the enantioselective hydrolysis of the title ester, PPL was selected from a series of esterases and lipases, and its enantioselectivity was evaluated by changing the reaction medium parameters. The use of 1.6 mol?L–1 sodium sulfate in phosphate buffer (pH 7.2) improved the enantioselectivity allowing the formation of methyl (2R)-(+)-2-methyl-4-oxopentanoate and (2S)-(–)-2-methyl-4-oxopentanoic acid with an enantiomeric excess of >99% and 71%, respectively. The study showed that a modulation of PPL enantioselectivity could be achieved by using kosmotropic salts in the reaction media. The present method consists of a practical and low-cost option to improve enzymatic kinetic resolution reactions.
Inducing Enantioselectivity in a Dynamic Catalyst by Supramolecular Interlocking
Scholtes, Jan Felix,Trapp, Oliver
supporting information, p. 6306 - 6310 (2019/04/03)
The design of a new class of fluxional biphenyl bisphosphinite (BIBIPHOS) ligands decorated with amino acid-based diamide interaction sites is reported that undergo spontaneous desymmetrization. Hydrogenation of prochiral alkenes using Rh-BIBIPHOS results
Enantioselectivity Induced by Stereoselective Interlocking: A Novel Core Motif for Tropos Ligands
Scholtes, Jan Felix,Trapp, Oliver
, p. 11707 - 11714 (2019/08/16)
Well-defined supramolecular interactions are a powerful tool to control the stereochemistry of a catalytic reaction. In this paper, we report a novel core motif for fluxional 2,2′-biphenyl ligands carrying (S)-amino acid-derived interaction sites in 5,5′-
Synthesis of the mycolactone core by ring-closing metathesis
Alexander, Matthew D.,Fontaine, Shaun D.,La Clair, James J.,DiPasquale, Antonio G.,Rheingold, Arnold L.,Burkart, Michael D.
, p. 4602 - 4604 (2007/10/03)
The undecenolide core of mycolactone was synthesized by ring-closing metathesis and the structure confirmed using single-crystal X-ray diffraction techniques. The Royal Society of Chemistry 2006.
Chiral diphosphites derived from D-glucose: new highly modular ligands for the asymmetric catalytic hydrogenation.
Dieguez, Montserrat,Ruiz, Aurora,Claver, Carmen
, p. 3796 - 3801 (2007/10/03)
A series of novel diphosphite ligands derived from readily available D-(+)-glucose have been synthesized. These ligands were screened in the Rh-catalyzed hydrogenation of a series of alpha,beta-unsaturated carboxylic acid derivatives. Both excellent enantioselectivities (ee up to >99%) and activities were achieved. The advantage of these ligands is that their modular nature allows an easy systematic variation in the configuration of the stereocenters (C-3, C-5) at the ligand backbone and in the biaryl substituents, so the optimum configuration for maximum enantioselectivity in asymmetric hydrogenation can be determined. Results show that enantiomeric excesses depend strongly on the absolute configuration of C-3 and slightly on the stereocenter carbon C-5, while the sense of the enantiodiscrimination is predominantly controlled by the configuration of the biaryls at the phosphite moieties. Moreover, the presence of bulky substituents at the ortho-positions of the biaryl diphosphite moieties has a positive effect on enantioselectivity.
Chiral phosphite-phosphoroamidites: A new class of ligand for asymmetric catalytic hydrogenation
Dieguez,Ruiz,Claver
, p. 2702 - 2703 (2007/10/03)
A series of novel phosphite-phosphoroamidite ligands, derived from readily available D-xylose, has been used for the first time in the asymmetric Rh-catalyzed hydrogenation of a series of α,β-unsaturated carboxylic acid derivatives with excellent enantios
The Stereoselective Synthesis of 2-Alkyl γ-Keto Acid and Heterocyclic Ketomethylene Peptide Isostere Core Units Using Chiral Alkylation by 2-Triflyloxy Esters
Hoffman, Robert V.,Kim, Hwa-Ok
, p. 5107 - 5113 (2007/10/02)
A simple and general protocol for the enentioselective preparation of γ-keto acids and heterocyclic γ-keto acids which have an alkyl group at C-2 is reported.The alkyl group is introduced by chiral alkylation using a scalemic 2-triflyoxy ester.The alkylation takes place with inversion of configuration and is compatible with a variety of alkyl groups.This methodology is thus wellsuited for the preparation of a wide variety of ketomethylene peptide isosteres.
A new chiral alkylation methodology for the synthesis of 2-alkyl-4-ketoacids in high optical purity using 2-triflyloxy esters
Hoffman, Robert V.,Kim, Hwa-Ok
, p. 2051 - 2054 (2007/10/02)
Optical active 2-triflyloxy esters are excellent alkylating agents for β-ketoester enolates. Decarboxylation of the alkylation products gives 2-substituted-4-ketoacid derivatives in high optical purities.
