Regio- and Enantioselective Synthesis of Azole Hemiaminal Esters by Lewis Base Catalyzed Dynamic Kinetic Resolution

J Am Chem Soc. 2016 Apr 13;138(14):4818-23. doi: 10.1021/jacs.6b00207. Epub 2016 Mar 30.

Abstract

We report a modular three-component dynamic kinetic resolution (DKR) that affords enantiomerically enriched hemiaminal esters derived from azoles and aldehydes. The novel and scalable reaction can be used to synthesize valuable substituted azoles in a regioselective manner by capping (e.g., acylation) of the equilibrating azole-aldehyde adduct. With the use of a prolinol-derived DMAP catalyst as the chiral Lewis base, the products can be obtained in high chemical yield and with high enantiomeric excess. The DKR was performed on a multikilogram scale to produce a tetrazole prodrug fragment for a leading clinical candidate that posed formidable synthesis challenges.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aldehydes / chemistry
  • Alkanesulfonates / chemical synthesis
  • Alkanesulfonates / chemistry
  • Azoles / chemical synthesis*
  • Azoles / chemistry
  • Catalysis
  • Esters / chemical synthesis*
  • Esters / chemistry
  • Kinetics
  • Lewis Bases / chemistry*
  • Stereoisomerism
  • Tetrazoles

Substances

  • Aldehydes
  • Alkanesulfonates
  • Azoles
  • Esters
  • Lewis Bases
  • Tetrazoles