An aldol-based build/couple/pair strategy for the synthesis of medium- and large-sized rings: discovery of macrocyclic histone deacetylase inhibitors

J Am Chem Soc. 2010 Dec 1;132(47):16962-76. doi: 10.1021/ja105119r. Epub 2010 Nov 10.

Abstract

An aldol-based build/couple/pair (B/C/P) strategy was applied to generate a collection of stereochemically and skeletally diverse small molecules. In the build phase, a series of asymmetric syn- and anti-aldol reactions were performed to produce four stereoisomers of a Boc-protected γ-amino acid. In addition, both stereoisomers of O-PMB-protected alaninol were generated to provide a chiral amine coupling partner. In the couple step, eight stereoisomeric amides were synthesized by coupling the chiral acid and amine building blocks. The amides were subsequently reduced to generate the corresponding secondary amines. In the pair phase, three different reactions were employed to enable intramolecular ring-forming processes: nucleophilic aromatic substitution (S(N)Ar), Huisgen [3+2] cycloaddition, and ring-closing metathesis (RCM). Despite some stereochemical dependencies, the ring-forming reactions were optimized to proceed with good to excellent yields, providing a variety of skeletons ranging in size from 8- to 14-membered rings. Scaffolds resulting from the RCM pairing reaction were diversified on the solid phase to yield a 14 400-membered library of macrolactams. Screening of this library led to the discovery of a novel class of histone deacetylase inhibitors, which display mixed enzyme inhibition, and led to increased levels of acetylation in a primary mouse neuron culture. The development of stereo-structure/activity relationships was made possible by screening all 16 stereoisomers of the macrolactams produced through the aldol-based B/C/P strategy.

Publication types

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

MeSH terms

  • Aldehydes / chemistry*
  • Animals
  • Biological Products / chemical synthesis
  • Biological Products / chemistry
  • Biological Products / pharmacology
  • Drug Discovery / methods*
  • Drug Evaluation, Preclinical
  • Histone Deacetylase Inhibitors / chemical synthesis*
  • Histone Deacetylase Inhibitors / chemistry
  • Histone Deacetylase Inhibitors / pharmacology*
  • Histone Deacetylases / metabolism*
  • Macrocyclic Compounds / chemical synthesis*
  • Macrocyclic Compounds / chemistry
  • Macrocyclic Compounds / pharmacology*
  • Mice
  • Models, Molecular
  • Molecular Conformation
  • Stereoisomerism
  • Substrate Specificity

Substances

  • Aldehydes
  • Biological Products
  • Histone Deacetylase Inhibitors
  • Macrocyclic Compounds
  • 3-hydroxybutanal
  • Histone Deacetylases