1,4-Naphthoquinone

(A) Using 1,4-naphthoquinone (1) as arylation reagent, Jorgensen and co-workers realized the highly enantioselective α-arylation of aldehydes 2, affording α-arylated products 4 with a dihydroquinone functionality.⁶ (B) Zhou⁷ and Wang & Jiang⁸ independently reported the organocatalytic asymmetric Michael addition of oxindole 5 to 1,4-naphthoquinone, which could furnish the 3,3-disubstituted oxindoles 6 that are widely presented in natural products and pharmaceutically active compounds. (C) In the presence of phosphoric acid 8, the asymmetric 1,3-dipolar cycloaddition of 1,4-naphthoquinone 1 with in situ generated azomethine ylides from aldehydes 2 and diethyl aminomalonate 7 was achieved by Gong and co-workers, which afforded the biologically active isoindolines 9 with excellent yield and ee.⁹.