Convenient synthesis of selected meta- and ortho-substituted pentaarylpyridines via the Suzuki-Miyaura cross-coupling reaction

Piotr Pomarański, Piotr Roszkowski, Jan K. Maurin, Armand Budzianowski, Zbigniew Czarnocki

Tetrahedron Letters, 
Volume 58, Issue 5, 1 February 2017, Pages 462–465
 http://dx.doi.org/10.1016/j.tetlet.2016.12.064

Abstract

The first synthesis of sterically demanding, stable at room temperature atropisomeric derivatives of penta-(ortho-substituted phenyl)pyridines is described. The Suzuki-Miyaura cross-coupling reaction of pentabromopyridine and selected meta- and ortho-tolylboronic acids afforded a series of pentaarylpyridine derivatives. The structures of two room temperature stable atropisomeric derivatives of penta-(o-tolyl)pyridines were confirmed by single-crystal X-ray analysis. Racemic atropisomers were examined by 1H NMR spectroscopy with a chiral solvating agent in order to visualize the presence of individual enantiomers.

Download: