Enantioselective Catalyst Systems from Copper(II) Triflate and BINOL–Silanediol

• Published in: Chemistry : a European journal Vol. 24; no. 28; pp. 7123 - 7127
• Main Authors: Guan, Yong, Attard, Jonathan W., Visco, Michael D., Fisher, Thomas J., Mattson, Anita E.
• Format: Journal Article
• Language: English
• Published: WEINHEIM Wiley 17.05.2018; Wiley Subscription Services, Inc
• Subjects: Adducts; Alkylidene; Catalysis; Catalysts; Chemistry; Chemistry, Multidisciplinary; cooperative catalysis; Copper; Copper compounds; Enantiomers; enantioselectivity; Friedel–Crafts reactions; Indoles; Lewis acid; Naphthol; Physical Sciences; Science & Technology; silanediols; enantioselectivity; Friedel-Crafts reactions; ACIDS; cooperative catalysis; copper; silanediols; ANION RECOGNITION; FRIEDEL-CRAFTS ALKYLATION; PROTEASE INHIBITORS; INDOLES
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.201801304

Silanediol and copper catalysis are merged, for the first time, to create an enhanced Lewis acid catalyst system for enantioselective heterocycle functionalization. The promise of this silanediol and copper catalyst combination is demonstrated in the enantioselective addition of indoles to alkylidene malonates to give rise to the desirable adducts in excellent yield and high enantiomeric excess. From these studies, 1,1′‐bi‐2‐naphthol (BINOL)‐based silanediols emerge as one‐of‐a‐kind cocatalysts. Their potential role in the reaction pathway is also discussed. Better together: Silanediol and copper(II) triflate work together to create an enhanced catalyst system for enantioselective heterocycle functionalization. This unique catalyst combination activates alkylidene malonates for reaction with indoles to give rise to desirable products in excellent yield and high levels of enantiomeric excess (see figure).