Organic & Biomolecular Chemistry, Journal Year: 2024, Volume and Issue: 22(7), P. 1365 - 1368
Published: Jan. 1, 2024
We applied post-cyclization annulation to introduce a series of tethered S-shaped double [4]helicenes in which the intramolecular tether imposes specific helical handedness, while length determines helicene's pitch.
Language: Английский
Chemical Science, Journal Year: 2025, Volume and Issue: unknown
Published: Jan. 1, 2025
We report the synthesis and characterization of nanographene–Re complexes investigate Re( i )-induced structural chiral transformations in nanographene.
Language: Английский
Citations
0
Chemical Science, Journal Year: 2023, Volume and Issue: 14(15), P. 3963 - 3972
Published: Jan. 1, 2023
Base-mediated intermolecular macrocyclization and Rh- or Ni-catalyzed intramolecular double [2 + 2 2] cycloadditions allow enantio- diastereoselective synthesis of planar chiral [2.2]triphenylenophanes.
Language: Английский
Citations
9
Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(45), P. 31114 - 31123
Published: Oct. 30, 2024
Transition metal carbenes have emerged as versatile intermediates for various types of alkylations. While reactions carbene species with alkenes been extensively studied, most examples focus on cyclopropanation and allylic C-H insertion. Herein, we present the first example a catalytic strategy carbene-involved regioselective remote alkylation internal olefins by synergistically combining two iridium-mediated reactivities olefin chain walking carbenoid migratory The method, utilizing sulfoxonium ylides bench-stable robust precursor, was found to be effective series tethered alkyl chains, heteroatom substituents, complex biorelevant moieties. Combined experimental computational studies revealed that reversible iridium hydride-mediated proceeds lead terminal alkyl-Ir intermediate, which then forms final insertion, resulting in terminal-alkylated products.
Language: Английский
Citations
3
Angewandte Chemie, Journal Year: 2024, Volume and Issue: 136(9)
Published: Jan. 10, 2024
Abstract We report the helicoselective and convergent construction of indolohelicenoids with excellent efficiency stereocontrol. This reaction proceeds through a chiral‐phosphoric‐acid‐catalyzed enantioselective cycloaddition eliminative aromatization sequence, which can be finely controlled by adjusting temperature. Mechanistic studies reveal that chiral phosphoric acid cooperatively serves as both bifunctional Brønsted catalyst, enabling one‐pot central‐to‐helical chirality conversion. Additionally, optical properties synthesized were characterized to explore their potential applications in organic photoelectric materials.
Language: Английский
Citations
2
Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(26)
Published: April 24, 2024
A pair of enantiopure [6]-azairidahelicenes incorporating chirality at the metal center and on helicenic ligand were synthesized by dynamic kinetic resolution (dkr) a configurationally labile [4]-helicenic (4-(2-pyridyl)-benzo[g]phenanthrene, L1H) using bis-cyclometalated chiral-at-metal only iridium(III) precursors as chiral inductors. The origin observed dkr is attributed to different conformation stability diastereomeric reaction intermediates formed during cyclometalation process. isolated enantiomers exhibited circularly polarized phosphorescence (CPP), with |g
Language: Английский
Citations
2
Chemistry - A European Journal, Journal Year: 2023, Volume and Issue: 29(58)
Published: July 17, 2023
We describe a concise synthetic strategy for the preparation of heterocyclic [9]helicenes and simple preparative-scale protocol optical resolution resulting M- P-enantiomers. The helicenes were characterized by single-crystal X-ray diffraction along with range spectroscopic computational techniques. A fluorescence quantum yield up to 65 % was observed, chiroptical properties both P-helicenes revealed large dissymmetry factors. circularly polarized luminescence brightness reaches 17 M-1 cm-1 , as measured experimentally verified computationally, which makes this highest among helicenes. how (both circular dichroism luminescence) can be described predicted using chemical calculations. approach also reveals by-products that originate from internal oxidation reactions, presumably mediated close proximity π-surfaces in helicene structure.
Language: Английский
Citations
6
Chemistry - A European Journal, Journal Year: 2023, Volume and Issue: 30(3)
Published: Oct. 23, 2023
Two new pentagon-embedded carbo[11]helicenes have been designed and synthesized in a three-step process, which are the first example of through post-functionalization twistacene. TD-DFT analyses indicate that both them possess high enantiomerization barriers 42.29 kcal/mol 40.76 kcal/mol, respectively. They emit strong red fluorescence can be chemically oxidized into stable cationic radicals upon addition AgSbF
Language: Английский
Citations
5
Chemistry - A European Journal, Journal Year: 2022, Volume and Issue: 28(65)
Published: Oct. 7, 2022
Small chiral organic molecules with CD properties are in high demanded due to their potential use promising electronic and biological applications. Herein, we reveal a system which the oxidation of phosphino group corresponding phosphine oxide on inner rim helicene derivative induces CPL response. Laterally π-extended 7,8-dihydro[5]helicenes bearing groups helical rims (i. e., C1 position) were synthesized, structures unambiguously determined by X-ray crystallography. The photophysical (UV/visible emission) chiroptical these compounds investigated various solvents. Despite structural similarities, showed significantly better response than phosphine, dissymmetry factor for emission (|glum |=(1.3-1.9)×10-3 ) that can be attributed changes interior helix.
Language: Английский
Citations
8
Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(31)
Published: June 2, 2023
Abstract Chiral amines are broadly used compounds in pharmaceutical industry and organic synthesis, reductive amination reactions have been the most appreciated methods for their syntheses. However, one‐step transfer hydrogenative direct asymmetric (THDARA) that could expand scope, simplify operation eliminate use of additives has challenging. In this work, based on Xiao's racemic 2010 our recent work novel chiral pyridine ligands, half‐sandwich iridium catalysts were rationally designed synthesized. Using optimized catalyst azeotropic mixture formic acid triethylamine as hydrogen source, a broad range α‐chiral (hetero)aryl amines, including various polar functional groups heterocycles, prepared generally high yield enantioselectivity under mild operationally simple conditions. Density theory (DFT) calculation catalytically active Ir−H species key hydride step supported pyridine‐induced stereospecific generation center, enantioselection by taming highly flexible transition structure with multiple attractive non‐covalent interactions. This introduced type effective simplified approach to medicinally important well rare example robust enantioselective transition‐metal catalysis.
Language: Английский
Citations
4
European Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 27(41)
Published: July 19, 2024
Abstract Chiral helicenes are widely used in fields related to organic materials and molecular machines relevant molecules, as well serving privileged frameworks for chiral ligands catalysts. Therefore, the research into asymmetric routes synthesis of helical compounds has garnered significant interest recent years. In this regard, chirality conversion/transfer from precursors emerged a powerful strategy construction helicenes, allowing various types compounds. This become will remain prominent topic field synthesis. review article, described between 2012 2024, approaches by conversion or transfer centrally summarized.
Language: Английский
Citations
1