title: Fully regiocontrolled polyarylation of pyridine.
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.
authors.affiliation: Laboratoire d'Innovation Thérapeutique, UMR7200 CNRS-Université de Strasbourg , 74 route du Rhin, BP 60024, 67401 Illkirch, France.
authors.forename: Christelle
authors.initials: C
authors.lastname: Doebelin
authors.forename: Patrick
authors.initials: P
authors.lastname: Wagner
authors.forename: Frédéric
authors.initials: F
authors.lastname: Bihel
authors.forename: Nicolas
authors.initials: N
authors.lastname: Humbert
authors.forename: Cyril Assongo
authors.initials: CA
authors.lastname: Kenfack
authors.forename: Yves
authors.initials: Y
authors.lastname: Mely
authors.forename: Jean-Jacques
authors.initials: JJ
authors.lastname: Bourguignon
authors.forename: Martine
authors.initials: M
authors.lastname: Schmitt
mesh_terms: D054879:Halogenation; D015394:Molecular Structure; D011725:Pyridines / Q000138:chemical synthesis* / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D011725:Pyridines; C000591101:2-chloro-3-hydroxypyridine