Mechanism-Based Enantiodivergence in Manganese Reduction Catalysis: A Chiral Pincer Complex for the Highly Enantioselective Hydroboration of Ketones
| Autor: | Hubert Wadepohl, Vladislav Vasilenko, Clemens K. Blasius, Lutz H. Gade |
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| Rok vydání: | 2017 |
| Předmět: |
chemistry.chemical_classification
Ketone 010405 organic chemistry Aryl Enantioselective synthesis General Medicine General Chemistry Isoindoline 010402 general chemistry 01 natural sciences Catalysis 0104 chemical sciences chemistry.chemical_compound Hydroboration chemistry Organic chemistry Pincer ligand Alkyl |
| Zdroj: | Angewandte Chemie International Edition. 56:8393-8397 |
| ISSN: | 1433-7851 |
| DOI: | 10.1002/anie.201704184 |
| Popis: | A manganese alkyl complex containing a chiral bis(oxazolinyl-methylidene)isoindoline pincer ligand is a precatalyst for a catalytic system of unprecedented activity and selectivity in the enantioselective hydroboration of ketones, thus producing preparatively useful chiral alcohols in excellent yields with up to greater than 99 % ee. It is applicable for both aryl alkyl and dialkyl ketone reduction under mild reaction conditions (TOF >450 h−1 at −40 °C). The earth-abundant base-metal catalyst operates at very low catalyst loadings (as low as 0.1 mol %) and with a high level of functional-group tolerance. There is evidence for the existence of two distinct mechanistic pathways for manganese-catalyzed hydride transfer and their role for enantiocontrol in the selectivity-determining step is presented. |
| Databáze: | OpenAIRE |
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