Asymmetric palladium-catalyzed annulation of benzene-1,2-diol and racemic secondary propargylic carbonates bearing two different substituents
| Autor: | Celine Damez, Paul Lhoste, Jean-Robert Labrosse, Denis Sinou, Boguslaw Kryczka, Bouchra Rhers, Norbert Dominczak |
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| Přispěvatelé: | Méthodologie de synthèse et molécules bioactives (MSMB), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon, Łódź University of Technology, Université Claude Bernard Lyon 1 (UCBL), Université de Lyon |
| Rok vydání: | 2005 |
| Předmět: |
Annulation
010405 organic chemistry Ligand Organic Chemistry Diol Chiral ligand Enantioselective synthesis Protonation [CHIM.CATA]Chemical Sciences/Catalysis 010402 general chemistry 01 natural sciences Biochemistry Medicinal chemistry 0104 chemical sciences chemistry.chemical_compound chemistry Drug Discovery Propargyl Enantiomer |
| Zdroj: | Tetrahedron Tetrahedron, Elsevier, 2005, 61, pp.2589-2599. ⟨10.1016/j.tet.2005.01.084⟩ |
| ISSN: | 0040-4020 |
| DOI: | 10.1016/j.tet.2005.01.084 |
| Popis: | The palladium-catalyzed cyclization of benzene-1,2-diol with various racemic secondary propargyl carbonates having no acetylenic hydrogen in the presence of (R)-Binap as the chiral ligand afforded the two regioisomers of the corresponding 2,3-dihydro-1,4-dioxin derivatives in quite good yields, and also in enantioselectivities going from 40 to 97%. The cyclization of benzene-1,2-diol with methyl (R)-1-methyl-3-phenylpro-2-yn-1-yl carbonate in the presence of dppb as the achiral ligand afforded 2-benzylidene-3-methyl-2,3-dihydro-1,4-benzodioxine as the major product with 15% ee. The use of (R)-Binap as the chiral ligand afforded the (+) cyclized compound in 45% ee, when the (−) enantiomer was obtained with 77% ee in the presence of (S)-Binap. All the results suggest that in this case the enantioselective step is the diastereoselective protonation of the palladium–carbene intermediates. |
| Databáze: | OpenAIRE |
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