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A Two-Step Protocol for Umpolung Functionalization of Ketones Via Enolonium Species
Published on: August 16, 2018
Lithium binaphtholate-catalyzed enantioselective enyne addition to ketones: access to enynylated tertiary alcohols
1Department of Chemistry, Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University , and Collaborative Innovation Centre of Chemical Science and Engineering (Tianjin) , Tianjin 300072, China.
Abstract:
A new catalytic enantioselective enyne addition to ketones has been developed. In the presence of chiral lithium binaphtholate, the addition reaction proceeded smoothly to produce a series of enynylated tertiary alcohols in up to 96% yield and 94% enantiomeric excess. Convenient transformation of the adduct via Pauson-Khand cycloaddition reaction afforded the bicyclic product without detectable loss of enantioselectivity. Furthermore, catalytic asymmetric enyne addition to trifluoromethylketone was applied in the synthesis of the Efavirenz analogue.
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