Enantioselective Assembly of Cycloenones with a Nitrile-Containing All-Carbon Quaternary Center from Malononitriles Enabled by Ni Catalysis
Chiral nitriles are valuable molecules in modern organic synthesis and drug discovery. Selectively differentiating the two nitrile groups of widely available malononitrile derivatives is a straightforward yet underdeveloped route to construct enantioenriched nitriles. Here we report an enantioselective nickel-catalyzed desymmetrization of malononitriles for the generation of nitrile-containing all-carbon quaternary stereocenters. This protocol involves a nickel-catalyzed addition of aryl boronic acids to alkynes, followed by a selective nitrile insertion, providing unprecedented access to enantioenriched 5-7-membered α-cyano-cycloenones with a fully substituted olefin from a broad range of substrates. The synthetic utility of these nitrile products is demonstrated by gram-scale synthesis and conversion to several useful functional groups.
The invention provides a preparation method of p-phenylbutoxybenzoic acid. 3-alkynyl-1-butanol is used as a raw material, a catalyst is added, and p-phenylbutoxybenzoic acid is synthesized through four-step reaction. The preparation method comprises the f
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Paragraph 0052-0053
(2020/07/13)
Rhodium-Catalyzed asymmetric synthesis of spirocarbocycles: arylboron reagents as surrogates of 1,2-dimetalloarenes
(Figure Presented) Revolutionary Rh-oad: A rhodium/dienecatalyzed addition of sodium tetraarylborates to alkyne-tethered 2-cydoalken-lones has been developed for the synthesis of splrocarbocycles. The tetraarylborates catalytlcally form two new carbon-carbon bonds. A chlral diene ligand also asymmetrically creates quaternary spirocarbon stereocenters with high enantiomeric purity.