Enantioselective Conjugate Additions of 2‑Alkoxycarbonyl-3(2H)‑furanones

• Published in: Organic letters Vol. 20; no. 22; pp. 7085 - 7089
• Main Authors: Vojáčková, Petra, Chalupa, David, Prieboj, Jozef, Nečas, Marek, Švenda, Jakub
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 16.11.2018; Amer Chemical Soc
• Subjects: Chemistry; Chemistry, Organic; Physical Sciences; Science & Technology; ASYMMETRIC-SYNTHESIS; 1,3-DICARBONYL COMPOUNDS; ADJACENT QUATERNARY; PRODUCT; 2-SUBSTITUTED BENZOFURAN-3(2H)-ONES; 3(2H)-FURANONES; BETA-KETO-ESTERS; MICHAEL ADDITIONS; ROCAGLAMIDE; CYCLIZATION
• ISSN: 1523-7060; 1523-7052
• DOI: 10.1021/acs.orglett.8b03039

Enantioselective conjugate additions of in situ generated 2-alkoxycarbonyl-3­(2H)-furanones to three distinct types of π-electrophiles (terminal alkynones, α-bromo enones, and α-benzyl nitroalkenes) are reported. Catalysis by a nickel­(II)–diamine complex provided alkynone-derived adducts with high enantioselectivity, preferentially as the Z-isomers, and completely suppressed the undesired O-alkylation pathway. A cupreidine-based catalyst enabled extension of the enantioselective conjugate additions to α-bromo enones and α-benzyl nitroalkenes. The densely functionalized adducts that result are useful precursors to synthetic analogs of spirocyclic natural products pseurotins.