Lithium Binaphtholate-Catalyzed Enantioselective Enyne Addition to Ketones: Access to Enynylated Tertiary Alcohols
journal contributionposted on 20.06.2014, 00:00 by Hua Cai, Jing Nie, Yan Zheng, Jun-An Ma
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.