Published: Sept. 14, 2021
We report a method for the synthesis of chiral vicinal chlo-roamines via asymmetric protonation catalytically gener-ated prochiral chloroenamines using Brønsted acids. The process is highly enantioselective, with origin asymmetry and catalyst substituent effects elucidated by DFT calculations. show utility as an approach to broad range heterocycle-substituted aziridines treatment chloroamines base in one-pot process, well allow access diamines.
Language: Английский
Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(10), P. 4024 - 4031
Published: March 2, 2021
A novel enantioselective protonation protocol that is triggered by reductive cross coupling of olefins reported. When under cooperative photoredox and chiral hydrogen-bonding catalytic conditions using a terminal reductant, various α-branched vinylketones with diverse vinylazaarenes could provide important enantioenriched azaarene derivatives containing tertiary stereocenters at their remote δ-position high yields enantioselectivities. This reaction system also suitable for vinylazaarenes, thus successfully assembling elusive 1,4-stereocenters. The convenient late-stage modifications products, especially the formation ε-tertiary ε-heteroquaternary carbon stereocenters, further highlight synthetic value this method. Control experiments density functional theory (DFT) calculations were conducted to elucidate plausible mechanism origins regioselectivity stereoselectivity.
Language: Английский
Citations
102
Angewandte Chemie International Edition, Journal Year: 2020, Volume and Issue: 60(3), P. 1417 - 1422
Published: Oct. 8, 2020
Abstract Enantioselective protonation by hydrophosphinylation of diarylphosphine oxides with 2‐vinyl azaheterocycle N ‐oxide derivatives was demonstrated using chiral bis(guanidino)iminophosphorane as the higher‐order organosuperbase catalyst. It confirmed several control experiments that a weak conjugate acid bis(guanidino)iminophosphorane, instead achiral oxides, directly functioned proton source to afford corresponding product in highly enantioselective manner most cases. generated from would broaden scope reaction systems because utilization range less acidic pronucleophiles. This method is highlighted valuable synthesis series P,N‐ligands for metal complexes through reduction phosphine oxide and units without loss enantiomeric purity.
Language: Английский
Citations
43
Green Chemistry, Journal Year: 2022, Volume and Issue: 24(16), P. 6138 - 6144
Published: Jan. 1, 2022
With key steps involving electro-oxidation-triggered Smiles-type radical rearrangement and chemical reduction with SO 2 , a formal redox-neutral electrosynthesis for migratory heteroaryltrifluoromethylation of allylic amines was developed.
Language: Английский
Citations
25
Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(46)
Published: Aug. 26, 2022
Stereochemically defined organofluorine compounds are vital to drug discovery and many applicable catalytic strategies have been introduced for accessing these entities stereoselectively. One approach entails incorporation of a fluorine atom (C-F bond formation) or an moiety (e.g., CF3 CF2 H), another exploits commercially available with one more atoms. Here, we present the state-of-the-art regarding use alkenyl allylic fluorides in preparation stereochemically fluoro-organic molecules. Allylic may be purchased generated from acid, carboxylate salt, ester, aldehyde hydrate, ketone bearing several atoms next carbonyl group. We underscore untapped potential purchasable compounds, fluorides, as launching points development stereoselective processes that value therapeutic science.
Language: Английский
Citations
24
Advanced Synthesis & Catalysis, Journal Year: 2021, Volume and Issue: 363(13), P. 3170 - 3188
Published: April 19, 2021
Abstract The review summarizes recent advances in the synthesis of C2‐halogenated nitrogen heterocycles via nucleophilic halogenation corresponding N‐oxides as well application this methodology pharmaceuticals. Both scientific and patent literature is reviewed mostly over period last ten years. contains a practical guide (typical procedures infographic based on extensive analysis), which can help practitioners choosing optimal reagents/conditions for N‐heterocycles different types. bibliography 199 references. magnified image
Language: Английский
Citations
23
Chemistry - A European Journal, Journal Year: 2020, Volume and Issue: 26(53), P. 12249 - 12255
Published: June 15, 2020
Abstract A catalytic enantioselective synthesis of heterocyclic vicinal fluoroamines is reported. chiral Brønsted acid promotes aza‐Michael addition to fluoroalkenyl heterocycles give a prochiral enamine intermediate that undergoes asymmetric protonation upon rearomatization. The reaction accommodates range azaheterocycles and nucleophiles, generating the C−F stereocentre in high enantioselectivity, also amenable stereogenic C−CF 3 bonds. Extensive DFT calculations provided evidence for stereocontrolled proton transfer from catalyst substrate as rate‐determining step, showed importance steric interactions catalyst's alkyl groups enforcing enantioselectivity. Crystal structure data show dominance noncovalent core conformation, enabling modulation conformational landscape. Ramachandran‐type analysis conformer distribution Protein Data Bank mining indicated benzylic fluorination by this approach has potential improve potency several marketed drugs.
Language: Английский
Citations
20
Chemical Science, Journal Year: 2021, Volume and Issue: 13(3), P. 665 - 670
Published: Dec. 21, 2021
A ring-opening fluorination of bicyclic azaarenes was developed. Although this overall transformation can be classified as an electrophilic aromatics, it is a novel type that results in construction tert -C–F bonds.
Language: Английский
Citations
16
Membranes, Journal Year: 2022, Volume and Issue: 12(8), P. 809 - 809
Published: Aug. 21, 2022
In this paper, the compatibility of polyetherimide (PEI) with different contents as a high-performance copolymer and polyvinylidene fluoride (PVDF) was studied, 5%-20% PEI prepared by non-solvent-induced phase inversion method. The PVDF evaluated analyzing physical structure properties blend membrane, microstructure, glass transition temperature Tg, enthalpy, mechanism polymer enthalpy change. results show that membranes have -NH C=O-N binding energies at X-ray photoelectron spectroscopy (XPS), which preliminarily proves fluorine-amine bonds are formed between polymers, new spectra appeared Fourier transform infrared (FTIR) diffraction (XRD) peaks, further two formation bonds, Tg mixed membrane increased, scanning electron microscope (SEM) observed pores changed from finger-like to sponge-like macropores. When content is 15%, performance blended best, water contact angle increases 58.5°, porosity 17.33%, maximum force 8.04 N, elongation break decreases 24.26%, pure flux 1870.292 L/m2·h, oil rejection 87%. addition, change blending compatible systems good improvement for PVDF.
Language: Английский
Citations
9
Angewandte Chemie, Journal Year: 2020, Volume and Issue: 133(3), P. 1437 - 1442
Published: Oct. 8, 2020
Abstract Enantioselective protonation by hydrophosphinylation of diarylphosphine oxides with 2‐vinyl azaheterocycle N ‐oxide derivatives was demonstrated using chiral bis(guanidino)iminophosphorane as the higher‐order organosuperbase catalyst. It confirmed several control experiments that a weak conjugate acid bis(guanidino)iminophosphorane, instead achiral oxides, directly functioned proton source to afford corresponding product in highly enantioselective manner most cases. generated from would broaden scope reaction systems because utilization range less acidic pronucleophiles. This method is highlighted valuable synthesis series P,N‐ligands for metal complexes through reduction phosphine oxide and units without loss enantiomeric purity.
Language: Английский
Citations
12
Organic Chemistry Frontiers, Journal Year: 2022, Volume and Issue: 9(11), P. 3039 - 3044
Published: Jan. 1, 2022
A chiral NHC catalyst reacts with α,β-γ,δ-diunsaturated aldehydes to generate an extended Breslow intermediate. Upon δ-protonation and tautomerization, the resulting α,β-unsaturated acyl azolium undergoes [3 + 3] annulation enamines afford various dihydropyridinones.
Language: Английский
Citations
8