Cyclic (Aryl)(Amido)Carbenes: NHCs with Triplet‐like Reactivity
| Autor: | Prakash R. Sultane, Guillermo Ahumada, Daniel Janssen‐Müller, Christopher W. Bielawski |
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| Rok vydání: | 2019 |
| Předmět: |
Tolman electronic parameter
010405 organic chemistry Aryl Chemical shift General Medicine General Chemistry 010402 general chemistry 01 natural sciences Medicinal chemistry Catalysis 0104 chemical sciences Adduct chemistry.chemical_compound chemistry Electrophile Physical organic chemistry Reactivity (chemistry) Derivative (chemistry) |
| Zdroj: | Angewandte Chemie International Edition. 58:16320-16325 |
| ISSN: | 1521-3773 1433-7851 |
| DOI: | 10.1002/anie.201910350 |
| Popis: | The synthesis and study of a library of cyclic (aryl)(amido)carbenes (CArAmCs), which represent a class of electrophilic NHCs that feature low calculated singlet-triplet gaps (ΔEST =19.9 kcal mol-1 ; B3LYP/def2-TZVP) and exhibit reactivity profiles expected from triplet carbenes, are described. The electrophilic properties of the CArAmCs were quantified by analyzing their respective selenium adducts, which exhibited the largest downfield 77 Se NMR chemical shifts (up to 1645 ppm) measured for any NHC derivative known to date, as well as their Ir carbonyl complexes, from which large Tolman electronic parameter (TEP) values (up to 2064 cm-1 ) were ascertained. The CArAmCs were found to engage in reactions that are typically observed with triplet carbenes, including C-H insertions, [2+1] cycloadditions with alkenes as well as alkynes, and spontaneous oxidation upon exposure to oxygen. |
| Databáze: | OpenAIRE |
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