Modularly Evolved 2-AminoDMAP/Squaramides as Highly Active Bifunctional Organocatalysts in Michael Addition

Isik M., Unver M. Y., TANYELİ C.

JOURNAL OF ORGANIC CHEMISTRY, vol.80, no.2, pp.828-835, 2015 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 80 Issue: 2
  • Publication Date: 2015
  • Doi Number: 10.1021/jo5022597
  • Journal Name: JOURNAL OF ORGANIC CHEMISTRY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.828-835
  • Middle East Technical University Affiliated: Yes

Abstract

We report a new family of chiral bifunctional acid/base type organocatalysts, 2-aminoDMAP/Squaramides, which are proved to be highly active (1 mol % cat. loading) promoters in conjugate addition of dibenzoylmethane to various trans-beta-nitroalkenes. Steric demand of the catalysts was clearly seen by a set-by-set modulation of the squaramide unit through electronic and steric factors. The synergistic cooperation of 2-aminoDMAP "superbase" and sterically encumbered squaramide (H-bond donor) enabled complete conversion of a range of reactants into corresponding Michael adducts in a couple of hours with exquisite selectivities (up to 98% ee).