Cyclometalated N-heterocyclic carbene-platinum catalysts for the enantioselective cycloisomerization of nitrogen-tethered 1,6-enyne
| Autor: | Delphine Brissy, Angela Marinetti, Pascal Retailleau, Serafino Gladiali, Hélène Jullien, Jean-Valère Naubron, Remy Sylvain |
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| Přispěvatelé: | Institut de Chimie des Substances Naturelles (ICSN), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC) |
| Jazyk: | angličtina |
| Rok vydání: | 2011 |
| Předmět: |
Intramolecular reaction
Enyne 010405 organic chemistry Chemistry Stereochemistry [CHIM.ORGA]Chemical Sciences/Organic chemistry Enantioselective synthesis chemistry.chemical_element General Chemistry 010402 general chemistry 01 natural sciences Medicinal chemistry Oxidative addition 0104 chemical sciences chemistry.chemical_compound Cycloisomerization Platinum Enantiomeric excess Carbene ComputingMilieux_MISCELLANEOUS |
| Zdroj: | Advanced Synthesis and Catalysis Advanced Synthesis and Catalysis, Wiley-VCH Verlag, 2011, 353 (7), pp.1109-1124. ⟨10.1002/adsc.201000904⟩ |
| ISSN: | 1615-4150 1615-4169 |
| DOI: | 10.1002/adsc.201000904⟩ |
| Popis: | Platinum(II) complexes which combine six-membered N-heterocyclic carbene-containing metallacyclic units and monodentate chiral phosphines have been prepared. The key step of their synthesis is the intramolecular oxidative addition of N -2-iodobenzylimidazolylidene-platinum(0)-diene complexes in the presence of the chiral phosphorus ligands. The platinum(II) metallacycles have been used as well-defined pre-catalysts for the enantioselective cycloisomerization of nitrogen-tethered 1,6-enynes into 3-azabicyclo[4.1.0]hept-4-enes. High enantiomeric excesses have been obtained with either Monophos or phenyl-Binepine based catalysts ( ees =82–96%), although phenyl-Binepine outperforms Monophos in these reactions. The absolute configuration of the final 3-azabicyclo[4.1.0.]heptenes has been established by X-ray diffraction studies. The method has been extended then to the cycloisomerization of dienynes with enantiotopic vinyl groups. An ( S )-phenyl-Binepine-platinum(II) complex allows total diastereoselectivity and high enantioselectivity levels to be attained in these reactions ( ees up to 95%) which represent the first enantioselective desymetrizations achieved via enyne cycloisomerizations. |
| Databáze: | OpenAIRE |
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