Palladium-catalyzed coupling of arene C-H bonds with methyl- and arylboron reagents assisted by the removable 2-pyridylsulfinyl group

J Org Chem. 2011 Nov 18;76(22):9525-30. doi: 10.1021/jo2018137. Epub 2011 Oct 21.

Abstract

The Pd(II)-catalyzed direct coupling of arene C-H bonds with organoboron reagents assisted by the 2-pyridylsulfinyl group is reported. Methylboronic acid and arylboronic acid neopentyl esters proved to be efficient coupling partners, furnishing methylated arenes and biaryl products in moderate to good yields. The 2-pyridylsulfinyl group can be easily removed to provide the free biaryls. The essential role of the 2-pyridyl unit in stabilizing the cyclopalladation complex was demonstrated by X-ray diffraction analysis of the palladacycle intermediate.