Chiral Brønsted Acid from Chiral Phosphoric Acid Boron Complex and Water: Asymmetric Reduction of Indoles
| Autor: | Feng Zhang, Guan Zhang, Chenglan Wang, Yixian Lou, Liang-Wen Qi, Peiyuan Yu, Kai Yang, Wangyang Li, Tongchang Fang, Lu Zhou, Hetao Xu, Qiuling Song |
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| Rok vydání: | 2020 |
| Předmět: |
inorganic chemicals
Indole test In situ 010405 organic chemistry Enantioselective synthesis chemistry.chemical_element General Medicine General Chemistry 010402 general chemistry 01 natural sciences Combinatorial chemistry Catalysis 0104 chemical sciences chemistry.chemical_compound chemistry Functional group Boron Brønsted–Lowry acid–base theory Phosphoric acid |
| Zdroj: | Angewandte Chemie International Edition. 59:3294-3299 |
| ISSN: | 1521-3773 1433-7851 |
| DOI: | 10.1002/anie.201913656 |
| Popis: | A new chiral Brønsted acid, generated in situ from a chiral phosphoric acid boron (CPAB) complex and water, was successfully applied to asymmetric indole reduction. This "designer acid catalyst", which is more acidic than TsOH as suggested by DFT calculations, allows the unprecedented direct asymmetric reduction of C2-aryl-substituted N-unprotected indoles and features good to excellent enantioselectivities with broad functional group tolerance. DFT calculations and mechanistic experiments indicates that this reaction undergoes C3-protonation and hydride-transfer processes. Besides, bulky C2-alkyl-substituted N-unprotected indoles are also suitable for this system. |
| Databáze: | OpenAIRE |
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