Enantioselective Cyclizations of Silyloxyenynes Catalyzed by Cationic Metal Phosphine Complexes
Autor: | F. Dean Toste, Suyan Zhang, Jean-François Brazeau, Ignacio Colomer, Britton K. Corkey |
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Rok vydání: | 2012 |
Předmět: |
Phosphines
chemistry.chemical_element Alkyne Biochemistry Article Catalysis chemistry.chemical_compound Colloid and Surface Chemistry Cations Organic chemistry Organosilicon Compounds Enantiomeric excess chemistry.chemical_classification Molecular Structure Bicyclic molecule Cationic polymerization Enantioselective synthesis Stereoisomerism General Chemistry Combinatorial chemistry chemistry Cyclization Alkynes Gold Phosphine Palladium |
Zdroj: | Journal of the American Chemical Society. 134:2742-2749 |
ISSN: | 1520-5126 0002-7863 |
DOI: | 10.1021/ja210388g |
Popis: | The discovery of complementary methods for enantioselective transition metal-catalyzed cyclization with silyloxyenynes has been accomplished using chiral phosphine ligands. Under palladium catalysis, 1,6-silyloxyenynes bearing a terminal alkyne led to the desired five-membered ring with high enantioselectivities (up to 91% ee). As for reactions under cationic gold catalysis, 1,6- and 1,5-silyloxyenynes bearing an internal alkyne furnished the chiral cyclopentane derivatives with excellent enantiomeric excess (up to 94% ee). Modification of the substrate by incorporating an α,β-unsaturation led to the discovery of a tandem cyclization. Remarkably, using silyloxy-1,3-dien-7-ynes under gold catalysis conditions provided the bicyclic derivatives with excellent diastereo- and enantioselectivities (up to >20:1 dr and 99% ee). |
Databáze: | OpenAIRE |
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