N‐Heterocyclic Carbene Non‐Innocence in the Catalytic Hydrophosphination of Alkynes
| Autor: | Connie J. Isaac, William J. M. Blackaby, Michael K. Whittlesey, Samuel E. Neale, Stuart MacGregor, Sara Sabater |
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| Rok vydání: | 2019 |
| Předmět: |
Reaction mechanism
Chemistry media_common.quotation_subject Organic Chemistry Innocence Homogeneous catalysis homogeneous catalysis Catalysis Inorganic Chemistry reaction mechanisms chemistry.chemical_compound density functional calculations hydrophosphination Hydrophosphination Organic chemistry Physical and Theoretical Chemistry N-heterocyclic carbene Carbene media_common |
| Zdroj: | Blackaby, W J M, Neale, S E, Isaac, C J, Sabater, S, MacGregor, S A & Whittlesey, M K 2019, ' N-Heterocyclic Carbene Non-Innocence in the Catalytic Hydrophosphination of Alkynes ', ChemCatChem, vol. 11, no. 7, pp. 1893-1897 . https://doi.org/10.1002/cctc.201900220 |
| ISSN: | 1867-3899 1867-3880 |
| DOI: | 10.1002/cctc.201900220 |
| Popis: | Studies on alkyne hydrophosphination employing nickel-NHC catalysts (NHC=N-heterocyclic carbene) revealed that the free N-alkyl substituted NHCs themselves were catalytically active. DFT calculations showed the mechanism involves the NHC acting as a Brønsted base to form an imidazolium phosphide species which then undergoes rate-limiting nucleophilic attack at the terminal alkyne carbon. This mechanism explains the preference seen experimentally for reactions with aryl substituted phosphines and alkynes, while the rearrangements of the alkenyl anion formed upon P−C bond formation account for the observation of both Z- and E-regioisomers of the products. |
| Databáze: | OpenAIRE |
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