Here we describe a preliminary investigation on the ability of natural keratin to catalyze the nitroaldol (Henry) reaction between aldehydes and nitroalkanes. Both aromatic and heteroaromatic aldehydes bearing strong or moderate electron-withdrawing groups were converted into the corresponding β-nitroalcohol products in both DMSO and in water in the presence of tetrabutylammonium bromide (TBAB) as a phase transfer catalyst. Negligible background reactions (i.e., negative control experiment in the absence of keratin protein) were observed in these solvent systems. Aromatic aldehydes bearing electron-donating groups and aliphatic aldehydes showed poor or no conversion, respectively. In general, the reactions in water/TBAB required twice the amount of time than in DMSO to achieve similar conversions. Moreover, comparison of the kinetics of the keratin-mediated nitroaldol (Henry) reaction with other biopolymers revealed slower rates for the former and the possibility of fine-tuning the kinetics by appropriate selection of the biopolymer and solvent.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6272928 | PMC |
| http://dx.doi.org/10.3390/molecules21091122 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Multifunctional Magnetic Chiral HKUST MOF Decorated by Triazine, FeO, and Cu(l-Proline) Complex for Green and Mild Asymmetric Catalysis.
ACS Appl Mater Interfaces
December 2024
Department of Chemistry, Faculty of Sciences, Tarbiat Modares University, 14117-13116 Tehran, Islamic Republic of Iran.
A multifunctional magnetic chiral metal-organic framework (MOF) was developed for asymmetric applications by utilizing strategies of chiralization and multifunctionalization. Cu(l-proline)-Triazine/FeO@SiO-NH was employed as a chiral secondary agent to synthesize a chiral hybrid nanocomposite within a MOF. The use of a chiral secondary agent efficiently induces chirality in an achiral MOF structure that cannot be directly chiralized.
View Article and Find Full Text PDFDesign and application of intramolecular arylogous nitroaldol condensation to access 2-aryl-benzofuran and -indole derivatives and formal synthesis of saprisartan.
RSC Adv
November 2024
Department of Organic Synthesis and Process Chemistry, CSIR-Indian Institute of Chemical Technology (CSIR-IICT) Hyderabad 500 007 India
This study presents the design and application of intramolecular arylogous nitroaldol (Henry) condensation. A transition metal-free, base-mediated reaction of -heteroatom-substituted aryl aldehydes/ketones and 2-nitrobenzyl (pseudo)halides has been developed to access a wide range of 2-(2-nitroaryl)benzofuran/2-(2-nitroaryl)indole derivatives in high yields. The reaction appears to proceed through -/-benzylation and intramolecular arylogous nitroaldol condensation.
View Article and Find Full Text PDFSelectivity Control in Nitroaldol (Henry) Reaction by Changing the Basic Anion in a Chiral Copper(II) Complex Based on ()-2-Aminomethylpyrrolidine and 3,5-Di--butylsalicylaldehyde.
Molecules
November 2024
A.N. Nesmeyanov Institute of Organoelement Compounds of Russian Academy of Sciences (INEOS RAS), Vavilov Str. 28, Bld. 1, 119334 Moscow, Russia.
This article is a continuation of our previous research on the catalytic capability of a chiral copper complex based on commercially available ()-2-aminomethylpyrrolidine and 3,5-di--butylsalicylaldehyde with various counter-anions in the asymmetric Henry reaction. Our findings indicate that depending on the type of base used, chiral nitroalcohols with yields up to 98% and values up to 77%, as well as β-nitrostyrenes with yields up to 88%, can be produced. Additionally, it has been found that the outcome of the reaction and the catalytic properties of copper (II) complexes ()- and ()- are influenced by the structure of the aldehyde used.
View Article and Find Full Text PDFEvaluation of the enantioselectivity of new chiral ligands based on imidazolidin-4-one derivatives.
Beilstein J Org Chem
April 2024
Institute of Organic Chemistry and Technology, Faculty of Chemical Technology, University of Pardubice, Studentská 573, 532 10 Pardubice, Czech Republic.
The new chiral ligands based on derivatives of imidazolidin-4-one were synthesised and characterised. The catalytic activity and enantioselectivity of their corresponding copper(II) complexes were studied in asymmetric Henry reactions. It was found that the enantioselectivity of these catalysts is overall very high and depends on the relative configuration of the ligand used; configuration of ligand affords the nitroaldols with major enantiomer (up to 97% ee), whereas the application of ligands with -configuration led to nitroaldols with major -enantiomer (up to 96% ee).
View Article and Find Full Text PDFα-Methylbenzylamine Functionalized Crown-Ether-Appended Calix[4]arene Phase Transfer Catalyst for Enantioselective Henry Reaction.
Chemistry
December 2023
Sustainable Materials and Catalysis Research Laboratory (SMCRL) Department of Chemistry, Indian Institute of Technology Jodhpur, Jodhpur, 342037, India.
In this letter, we designed a highly selective α-methylbenzylamine functionalized crown-ether-appended calix[4]arene derived phase transfer catalyst for asymmetric nitroaldol reaction to provide the desired nitroaldol adducts in high yields (up to 99 % yield) with good to excellent enantioselectivities (up to 99.8 % ee).
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!