98%
921
2 minutes
20
The stereospecific synthesis of Z-enamides is described in this paper. For the first time, isoxazoles have been employed as electrophiles in C-H functionalization to afford thermodynamically less stable Z-enamides utilizing salicylaldehydes in an atom- and step-economic fashion. The stereochemistry of enamides might originate from the relative disposition of atoms present in isoxazole and the intramolecular hydrogen bonding. The reaction showed excellent scope as several structurally and electronically diverse salicylaldehydes and isoxazoles reacted efficiently.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/acs.orglett.8b04130 | DOI Listing |
PLoS One
June 2025
Natural Resource Ecology Laboratory, Colorado State University, Fort Collins, Colorado, United States of America.
Several alditol-2-dehydrogenase enzymes from the short chain dehydrogenase (SDR) family catalyze the production of enantiopure rare ketoses from alditols as substrates and are used in biotech industry. Clearly, the absolute configuration of the internal chiral carbons in the open-chain conformation of alditols provides the structural basis for the enzymatic operation. This also allows for substrate ambiguity that manifest as enzyme promiscuity due to partial stereoselectivity of the enzyme.
View Article and Find Full Text PDFAppl Microbiol Biotechnol
August 2024
State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, People's Republic of China.
Chemical synthesis of phosphoromonothioate oligonucleotides (PS-ONs) is not stereo-specific and produces a mixture of Rp and Sp diastereomers, whose disparate reactivity can complicate applications. Although the current methods to separate these diastereomers which rely on chromatography are constantly improving, many Rp and Sp diastereomers are still co-eluted. Here, based on sulfur-binding domains that specifically recognize phosphorothioated DNA and RNA in Rp configuration, we developed a universal separation system for phosphorothioate oligonucleotide isomers using immobilized SBD (SPOIS).
View Article and Find Full Text PDFNat Commun
May 2024
Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science (IBS), Daejeon, 34141, South Korea.
In recent decades, strategies involving transition-metal catalyzed carbon-carbon or carbon-heteroatom bond coupling have emerged as potent synthetic tools for constructing intricate molecular architectures. Among these, decarboxylative carbon-nitrogen bond formation using abundant carboxylic acids or their derivatives has garnered notable attention for accessing alkyl- or arylamines, one of key pharmacophores. While several decarboxylative amination methods have been developed, the involvement of a common carboradical intermediate currently poses challenges in achieving stereospecific transformation toward chiral alkylamines.
View Article and Find Full Text PDFMetabolites
October 2023
CIISA-Centro de Investigação Interdisciplinar em Sanidade Animal, Faculdade de Medicina Veterinária, Pólo Universitário do Alto da Ajuda, Universidade de Lisboa, Avenida da Universidade Técnica, 1300-477 Lisbon, Portugal.
Structured lipids (SLs) offer a promising avenue for designing novel formulations enriched in -3 long-chain polyunsaturated fatty acids (LCPUFAs) with potential health benefits. Triacylglycerols (TAGs), the most common fats in the human diet, are both non-toxic and chemically stable. The metabolic efficiency and digestibility of TAGs are significantly influenced by the position of fatty acids (FAs) within the glycerol backbone, with FAs at the -2 position being readily absorbed.
View Article and Find Full Text PDFChemistry
January 2024
School of Natural and Environmental Sciences - Chemistry, Newcastle University, Bedson Building, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK.
Vinyl ethers are valuable synthetic intermediates which are also found as natural products, including aflatoxins, rifamycins and plasmalogens. The latter are ubiquitous phospholipids in human cells and contain a vinyl ether moiety with specifically Z configuration. Although numerous methods are available for synthesis of vinyl ethers, there is a lack of methods for obtaining Z isomers of molecules of the type RCH=CHOR' that are applicable to plasmalogens.
View Article and Find Full Text PDF