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Li Y, Liou Y, Oliveira JCA, Ackermann L. Ruthenium(II)/Imidazolidine Carboxylic Acid-Catalyzed C-H Alkylation for Central and Axial Double Enantio-Induction. Angew Chem Int Ed Engl 2022; 61:e202212595. [PMID: 36108175 PMCID: PMC9828380 DOI: 10.1002/anie.202212595] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Indexed: 01/12/2023]
Abstract
Enantioselective C-H activation has surfaced as a transformative toolbox for the efficient assembly of chiral molecules. However, despite of major advances in rhodium and palladium catalysis, ruthenium(II)-catalyzed enantioselective C-H activation has thus far largely proven elusive. In contrast, we herein report on a ruthenium(II)-catalyzed highly regio-, diastereo- and enantioselective C-H alkylation. The key to success was represented by the identification of novel C2-symmetric chiral imidazolidine carboxylic acids (CICAs), which are easily accessible in a one-pot fashion, as highly effective chiral ligands. This ruthenium/CICA system enabled the efficient installation of central and axial chirality, and featured excellent branched to linear ratios with generally >20 : 1 dr and up to 98 : 2 er. Mechanistic studies by experiment and computation were carried out to understand the catalyst mode of action.
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Affiliation(s)
- Yanjun Li
- Institut für Organische und Biomolekulare ChemieGeorg-August-Universität GöttingenTammanstraße 237077GöttingenGermany
| | - Yan‐Cheng Liou
- Institut für Organische und Biomolekulare ChemieGeorg-August-Universität GöttingenTammanstraße 237077GöttingenGermany
| | - João C. A. Oliveira
- Institut für Organische und Biomolekulare ChemieGeorg-August-Universität GöttingenTammanstraße 237077GöttingenGermany
| | - Lutz Ackermann
- Institut für Organische und Biomolekulare ChemieGeorg-August-Universität GöttingenTammanstraße 237077GöttingenGermany
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Yang Y, Li N, Miao J, Cao X, Ying A, Pan K, Lv X, Ni F, Huang Z, Gong S, Yang C. Chiral Multi-Resonance TADF Emitters Exhibiting Narrowband Circularly Polarized Electroluminescence with an EQE of 37.2 . Angew Chem Int Ed Engl 2022; 61:e202202227. [PMID: 35536020 DOI: 10.1002/anie.202202227] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Indexed: 12/19/2022]
Abstract
Highly efficient circularly polarized luminescence (CPL) emitters with narrowband emission remain a formidable challenge for circularly polarized OLEDs (CP-OLEDs). Here, a promising strategy for developing chiral emitters concurrently featuring multi-resonance thermally activated delayed fluorescence (MR-TADF) and circularly polarized electroluminescence (CPEL) is demonstrated by the integration of molecular rigidity, central chirality and MR effect. A pair of chiral green emitters denoted as (R)-BN-MeIAc and (S)-BN-MeIAc is designed. Benefited by the rigid and quasi-planar MR-framework, the enantiomers not only display mirror-image CPL spectra, but also exhibit TADF properties with a high photoluminescence quantum yield of 96 %, a narrow FWHM of 30 nm, and a high horizontal dipole orientation of 90 % in the doped film. Consequently, the enantiomer-based CP-OLEDs achieved excellent external quantum efficiencies of 37.2 % with very low efficiency roll-off, representing the highest device efficiency of all the reported CP-OLEDs.
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Affiliation(s)
- Yiyu Yang
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060, P. R. China
| | - Nengquan Li
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060, P. R. China
| | - Jingsheng Miao
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060, P. R. China
| | - Xiaosong Cao
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060, P. R. China
| | - Ao Ying
- Department of Chemistry, Renmin Hospital of Wuhan University, Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Wuhan University, Wuhan, 430072, China
| | - Ke Pan
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060, P. R. China
| | - Xialei Lv
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060, P. R. China
| | - Fan Ni
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060, P. R. China
| | - Zhongyan Huang
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060, P. R. China
| | - Shaolong Gong
- Department of Chemistry, Renmin Hospital of Wuhan University, Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Wuhan University, Wuhan, 430072, China
| | - Chuluo Yang
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060, P. R. China
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