Rhodium‐Catalyzed Atroposelective Access to Axially Chiral Olefins via C−H Bond Activation and Directing Group Migration

Angewandte Chemie, Journal Year: 2021, Volume and Issue: 134(1)

Published: Oct. 22, 2021

Abstract Axially chiral open‐chain olefins represent an underexplored class of platform. In this report, two classes tetrasubstituted axially acyclic have been accessed in excellent enantioselectivity and regioselectivity via C−H activation (hetero)arenes assisted by a migratable directing group en route to coupling with sterically hindered alkynes. The indoles bearing N‐aminocarbonyl afforded C–N acrylamides the assistance racemic zinc carboxylate additive. DFT studies suggest β‐nitrogen elimination–reinsertion pathway for migration. Meanwhile, employment N‐phenoxycarboxamide delivered C−C enamides migration oxidizing group. Experiments that both cases (hetero)arene substrate adopts well‐defined orientation during activation, which turn determines disposition alkyne migratory insertion. Synthetic applications representative are demonstrated.

Language: Английский

---

Oxygen‐Linked Cyclopentadienyl Rhodium(III) Complexes‐Catalyzed Asymmetric C−H Arylation of Benzo[ h ]quinolines with 1‐Diazonaphthoquinones

Angewandte Chemie, Journal Year: 2021, Volume and Issue: 133(28), P. 15638 - 15644

Published: April 16, 2021

Abstract Chiral cyclopentadienyl rhodium (CpRh) complex‐catalyzed asymmetric C−H functionalization reactions have witnessed a significant progress in organic synthesis. In sharp contrast, the reported chiral Cp ligands are limited to C‐linked and often synthetically challenging. To address these issues, we developed novel class of tunable bearing oxygen linkers, which were efficient catalysts for arylation benzo[ h ]quinolines with 1‐diazonaphthoquinones, affording axially heterobiaryls excellent yields enantioselectivity (up 99 % yield, 98.5:1.5 er). Mechanistic studies suggest that reaction is likely proceed by electrophilic activation, followed coupling cyclometalated rhodium(III) complex 1‐diazonaphthoquinones.

Language: Английский

---

Circularly Polarized Fluorescence Resonance Energy Transfer (C‐FRET) for Efficient Chirality Transmission within an Intermolecular System

Angewandte Chemie, Journal Year: 2021, Volume and Issue: 133(46), P. 24754 - 24762

Published: Aug. 23, 2021

Abstract The occurrence and transmission of chirality is a fascinating characteristic nature. However, the intermolecular efficiency circularly polarized luminescence (CPL) remains challenging due to poor through‐space energy transfer. We report unique CPL from inducing achiral acceptor emit within specific liquid crystal (LC)‐based system through fluorescence resonance transfer ( C ‐FRET), wherein luminescent cholesteric LC employed as donor, rationally designed long‐wavelength aggregation‐induced emission (AIE) fluorophore acts well‐assembled acceptor. In contrast photon‐release‐and‐absorption, channel ‐FRET highly dependent upon in intrinsic chiral assembly LC, verified by deliberately separating donor keep it far beyond distance. This mode provides de novo strategy concept for high‐level information processing applications such high‐density data storage, combinatorial logic calculation, multilevel encryption decryption.

Language: Английский

---

Development of Chiral Ligands for the Transition‐Metal‐Catalyzed Enantioselective Silylation and Borylation of C−H Bonds

Angewandte Chemie, Journal Year: 2021, Volume and Issue: 134(9)

Published: Nov. 2, 2021

Abstract Enantioselective reactions that install functional groups at the positions of unactivated C−H bonds can be envisioned to produce intermediates for synthesis active ingredients in pharmaceuticals and agrochemicals directly from simple feedstocks. Among these bond functionalization reactions, those form carbon–silicon (C−Si) carbon–boron (C−B) have been pursued because products converted containing a wide range compounds silicon boron possess unique properties valuable medicinal materials chemistry. Although silylation borylation undergone extensive development during past two decades, enantioselective versions were not known until few years ago. In this Minireview, we present rapid bonds, with an emphasis on design types chiral ligands needed achieve intention inspire expansion transformations.

Language: Английский

---

Asymmetric Ru/Cinchonine Dual Catalysis for the One-Pot Synthesis of Optically Active Phthalides from Benzoic Acids and Acrylates

The Journal of Organic Chemistry, Journal Year: 2022, Volume and Issue: 87(7), P. 4617 - 4630

Published: March 10, 2022

Herein, we report the asymmetric Ru/cinchonine dual catalysis that provides straightforward access to enantioselective synthesis of C-3 substituted phthalides via tandem C–H activation/Michael addition cascade. The use readily accessible and less expensive [RuCl2(p-cym)]2 cinchonine catalyst for one-pot assembly chiral greatly overcomes present trend using highly sophisticated catalysts. developed method both enantiomers a product pseudoenantiomeric cinchona alkaloids as catalysts streamlining phthalide in optically active forms.

Language: Английский

---