Fully regiocontrolled polyarylation of pyridine

J Org Chem. 2014 Feb 7;79(3):908-18. doi: 10.1021/jo402200q. Epub 2014 Jan 22.

Abstract

Starting from commercially available 2-chloro-3-hydroxypyridine, a new route leading to the first protypical pentaarylpyridine bearing five different substituents is reported. This strategy involves a set of five sequential but fully regiocontrolled Suzuki-Miyaura reactions and highlights the 2-OBn pyridine protecting group as a key intermediate. The 2-OBn group played a double role: (i) it allowed additional bromination at position 5 and (ii) it could afford the reactive OTf species for the last C-arylation step at the less hindered 2 position of the tetraarylpyridine. The photophysical properties of the novel compounds are also described. The synthesized pentaarylpyridine derivative exhibit a large Stokes shift, strong solvatochromism, and quantum yield values up to 0.47; thus, they constitute promising building blocks for the design of environment-sensitive probes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Halogenation
  • Molecular Structure
  • Pyridines / chemical synthesis*
  • Pyridines / chemistry*
  • Stereoisomerism

Substances

  • Pyridines
  • 2-chloro-3-hydroxypyridine