Synfacts, Год журнала: 2023, Номер 19(12), С. 1249 - 1249
Опубликована: Ноя. 15, 2023
Key words amino acids - C–H activation nitrogen heterocycles photochemistry deracemization dipeptides
Язык: Английский
JACS Au, Год журнала: 2024, Номер 4(8), С. 2746 - 2766
Опубликована: Авг. 8, 2024
Photocatalysis is a versatile and rapidly developing field with applications spanning artificial photosynthesis, photo-biocatalysis, photoredox catalysis in solution or supramolecular structures, utilization of abundant metals organocatalysts, sustainable synthesis, plastic degradation. In this Perspective, we summarize conclusions from an interdisciplinary workshop young principal investigators held at the Lorentz Center Leiden March 2023. We explore how diverse fields within photocatalysis can benefit one another. delve into intricate interplay between these subdisciplines, by highlighting unique challenges opportunities presented each multidisciplinary approach drive innovation lead to solutions for future. Advanced collaboration knowledge exchange across domains further enhance potential photocatalysis. Artificial photosynthesis has become promising technology solar fuel generation, instance, via water splitting CO
Язык: Английский
Процитировано
17
Chemical Science, Год журнала: 2024, Номер 15(16), С. 5832 - 5868
Опубликована: Янв. 1, 2024
Organocatalytic asymmetric synthesis has evolved over the years and continues to attract interest of many researchers worldwide. Enantiopure noncanonical amino acids (ncAAs) are valuable building blocks in organic synthesis, medicinal chemistry, chemical biology. They employed elaboration peptides proteins with enhanced activities and/or improved properties compared their natural counterparts, as chiral catalysts, ligand design, for syntheses complex molecules, including products. The linkage ncAA enantioselective organocatalysis, subject this perspective, tries imitate biosynthetic process. Herein, we present contemporary earlier developments field organocatalytic activation simple feedstock materials, providing potential ncAAs diverse side chains, unique three-dimensional structures, a high degree functionality. These strategies, useful forging wide range C-C, C-H, C-N bonds combinations thereof, vary from classical name reactions, such Ugi, Strecker, Mannich most advanced concepts deracemisation, transamination, carbene N-H insertion. Concurrently, some interesting mechanistic studies/models, information on chirality transfer Finally, perspective highlights, through diversity (AAs) not selected by nature protein incorporation, generic modes activation, induction, reactivity commonly used, enamine, hydrogen bonding, Brønsted acids/bases, phase-transfer reflecting increasingly important role applied chemistry.
Язык: Английский
Процитировано
7
Accounts of Chemical Research, Год журнала: 2025, Номер unknown
Опубликована: Фев. 19, 2025
ConspectusMillions of chiral compounds contain a stereogenic sp3-hybridized carbon center with hydrogen atom as one the four different substituents. The can be edited in an increasing number cases by selective transfer (HAT) to and from photocatalyst. This Account describes development photochemical deracemization reactions using oxazole-annulated benzophenones bonding motif that allows them recognize lactam substrates two-point bonding. backbone catalysts consists azabicyclo[3.3.1]nonan-2-one U-shaped geometry, which enables substrate recognition occur parallel benzoxazole part aromatic ketones. photocatalysts facilitate catalytic several compound classes including hydantoins, N-carboxyanhydrides, oxindoles, 2,5-diketopiperazines, 4,7-diaza-1-isoindolinones. In addition, if more than is present, editing delivers distinct diastereoisomer upon appropriate selection respective photocatalyst enantiomer. operate via benzophenone triplet selectively abstracts properly positioned exclusively two enantiomers. step creates planar carbon-centered radical erases absolute configuration at this position. While returning HAT same position would likely recreate configuration, spectroscopic quantum chemical studies suggest delivered heteroatom conjugation center. Two scenarios distinguished for shuttling process. For 4,7-diaza-1-isoindolinones, back occurs carbonyl oxygen or imine-type nitrogen not involved binding catalyst. oxindoles single group available accept atom. It currently assumed group, although comparison former reaction pathway, latter process appears less efficient prone side reactions. both cases, achiral enol enamine formed, dissociation catalyst statistically either stereoisomers substrate. Since only enantiomer (or diastereoisomer) processed, high enantioselectivity diastereoselectivity) results. Even though contra-thermodynamic process, described decoupling thermal usage loadings vary between 2.5 10 mol % depending on specific mode action.
Язык: Английский
Процитировано
0
Frontiers in Microbiology, Год журнала: 2025, Номер 16
Опубликована: Апрель 1, 2025
Cyclic dipeptides represent a class of intriguing molecules with wide range biological activities, but their potential application as flavor precursors has not been previously reported. In this study, flavor-producing bacterium Bacillus velezensis was screened out from 35 isolated endophytic bacteria. Gas chromatography-mass spectrometry (GC-MS) analysis suggested that the fermentation broth B. contained compounds and high amount cyclic dipeptide precursors. Three precursors, namely cyclo (L-prolyl-L-valine) (1), (L-prolyl-L-isoleucine) (2), (L-prolyl-L-leucine) (3), were further extraction through Sephadex LH-20 column chromatography semi-preparative high-performance liquid (HPLC), identified by nuclear magnetic resonance (NMR) spectroscopy mass (MS). Flavor can generate aroma components during pyrolysis, pyrolysis 1 3 performed using GC-MS (Py-GC-MS) to analyze products. According relative odor activity value (ROAV) analysis, key revealed 6-heptyl-5,6-dihydro-2H-pyran-2-one, isobutyric acid, 4-methyl-2-oxo-pentanoic acid ester, pyrrole derivatives, pyrazine which could give great contributions milky, roasting, fruity, sweetness, nutty aromas. The formation pathway these also proposed in detail. Addition bacteria on cigar tobacco leaves significantly enhanced aromas, demonstrated enhancing ability dipeptides. This is first report effects utilized
Язык: Английский
Процитировано
0
Nachrichten aus der Chemie, Год журнала: 2025, Номер 73(4), С. 56 - 67
Опубликована: Март 31, 2025
Abstract Dieser Trendbericht erläutert Erkenntnisse der letzten beiden Jahre aus Sicht von Wissenschaftlerinnen und Wissenschaftlern des interdisziplinären, durch die DFG geförderten Konsortiums Transregio 325. Die Autorinnen Autoren forschen vor allem zu chemischer Photokatalyse beleuchten besonders Themen mit molekülchemischer Komponente.
Процитировано
0
Journal of the American Chemical Society, Год журнала: 2025, Номер unknown
Опубликована: Апрель 17, 2025
Deracemization of C(sp3)-H arylated carbonyl compounds faces limitations in terms substrate scope. Through the photoactivation aryl group and stereocontrol generated arene radical cation via asymmetric ion-pairing catalysis, we are able to achieve deracemization at both enolizable unenolizable stereocenters. A diverse range α-, β-, γ-aryl ketones esters, including natural products medicinal derivatives, can be effectively converted into their enantiomers with high enantioselectivity. Mechanistic investigations through combined experimental computational studies suggest that reaction involves single-electron oxidation electron-rich groups, followed by a kinetic resolution resulting intermediates chiral phosphate anion. Deprotonation is identified as stereodetermining step, while stereoselective back electron transfer triplet-state quenching 3 Mes-Acr1+* may also affect enantioselectivity photostationary state.
Язык: Английский
Процитировано
0
Journal of the American Chemical Society, Год журнала: 2024, Номер unknown
Опубликована: Ноя. 26, 2024
Desymmetrization of meso diols is an important strategy for the synthesis chiral oxygen-containing building blocks. Oxidative desymmetrization subclass, but existing methods are often constrained by need activated alcohol substrates. We disclose a conceptually distinct toward oxidative diol that enabled catalytic enantioselective hydrogen atom abstraction. Following single electron oxidation cinchona alkaloid-derived catalyst, enantiodetermining abstraction generates desymmetrized ketyl radical intermediate which reacts with either DIAD or O2 before in situ elimination to form valuable hydroxyketone products. A range cyclic and acyclic competent, defining absolute configuration up four stereocenters operation. As well as providing rapid access complex hydroxyketones, this work emphasizes broad synthetic potential harnessing manner.
Язык: Английский
Процитировано
3
Journal of the American Chemical Society, Год журнала: 2024, Номер unknown
Опубликована: Дек. 18, 2024
Photochemical deracemization has emerged as one of the most straightforward approaches to access highly enantioenriched compounds in recent years. While excited-state events such energy transfer, single electron and ligand-to-metal charge transfer have been leveraged promote stereoablation, relying on hydrogen atom which circumvent limitations imposed by triplet redox potential racemic substrates, remain underexplored. Conceptually, attractive method for tertiary stereocenter might be abstraction followed donation. However, implementing a strategy poses significant challenges, primarily because products are also reactive if chiral catalyst is unable differentiate between two enantiomers. Herein we report distinct dual photochemical δ- γ-lactams, achieving high enantioenrichment deuterium incorporation despite inherent reactivity products. Mechanistic studies reveal that benzophenone enables nonselective while tetrapeptide-derived thiol dictates enantioselectivity donation step. More importantly, pyridine-based alcohol was found play crucial roles facilitating well enhancing
Язык: Английский
Процитировано
3
Angewandte Chemie International Edition, Год журнала: 2024, Номер unknown
Опубликована: Окт. 16, 2024
Readily accessible, racemic N-carboxyanhydrides (NCAs) of α-amino acids underwent a deracemization reaction upon irradiation at λ=366 nm in the presence chiral benzophenone catalyst. The enantioenriched NCAs (up to 98 % ee) serve as activated acid surrogates and, due their instability, they were directly converted into consecutive products. N-Protected esters obtained after with MeOH and N-benzoylation (14 examples, 70 %-quant., 82-96 ee). Other reactions included amide (ten 65 90-98 peptide (three 75-89 %, d. r.=97/3 94/6) bond formation. Limitations method relate for some issues solubility, photooxidation, high configurational lability.
Язык: Английский
Процитировано
2
Angewandte Chemie International Edition, Год журнала: 2024, Номер unknown
Опубликована: Авг. 28, 2024
Cross conjugation, though prevalent in many organic compounds, is typically considered less effective for electron delocalization compared to linear conjugation. Consequently, it rarely used as the backbone structure semiconducting conjugated polymers. In this study, we designed and synthesized a novel building block, TIDP, which features central cyclic dipeptide with cross conjugation characteristics. Strong intramolecular hydrogen bonding interactions confer TIDP highly rigid coplanar conformation. Importantly, theoretical calculations reveal that π electrons are well delocalized across entire structure, despite its low aromaticity. Conjugated polymers incorporating exhibit high charge carrier mobilities, demonstrating of innovative block. Our findings show rational design, can achieve delocalization, providing valuable approach developing high-performance electronic materials.
Язык: Английский
Процитировано
1