Enantioselective Synthesis of N-Alkylamines through β-Amino C-H Functionalization Promoted by Cooperative Actions of B(C6F5)3 and a Chiral Lewis Acid Co-Catalyst

J Am Chem Soc. 2021 Feb 10;143(5):2441-2455. doi: 10.1021/jacs.0c13200. Epub 2021 Jan 29.

Abstract

We disclose a catalytic method for β-C(sp3)-H functionalization of N-alkylamines for the synthesis of enantiomerically enriched β-substituted amines, entities prevalent in pharmaceutical compounds and used to generate different families of chiral catalysts. We demonstrate that a catalyst system comprising of seemingly competitive Lewis acids, B(C6F5)3, and a chiral Mg- or Sc-based complex, promotes the highly enantioselective union of N-alkylamines and α,β-unsaturated compounds. An array of δ-amino carbonyl compounds was synthesized under redox-neutral conditions by enantioselective reaction of a N-alkylamine-derived enamine and an electrophile activated by the chiral Lewis acid co-catalyst. The utility of the approach is highlighted by late-stage β-C-H functionalization of bioactive amines. Investigations in regard to the mechanistic nuances of the catalytic processes are described.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkylation
  • Amines / chemical synthesis*
  • Amines / chemistry*
  • Carbon / chemistry*
  • Catalysis
  • Chemistry Techniques, Synthetic
  • Hydrogen / chemistry*
  • Lewis Acids / chemistry
  • Stereoisomerism

Substances

  • Amines
  • Lewis Acids
  • Carbon
  • Hydrogen