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Enantioselective cyclizations of silyloxyenynes catalyzed by cationic metal phosphine complexes.

ABSTRACT: 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 ?,?-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).

SUBMITTER: Brazeau JF

PROVIDER: S-EPMC3279184 | biostudies-literature | 2012 Feb

REPOSITORIES: biostudies-literature

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Enantioselective cyclizations of silyloxyenynes catalyzed by cationic metal phosphine complexes.

Brazeau Jean-François JF Zhang Suyan S Colomer Ignacio I Corkey Britton K BK Toste F Dean FD

Journal of the American Chemical Society 20120131 5

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 enanti ...[more]

PMID: 22296571

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