Ruthenium-Catalyzed Meta Sulfonation of 2-Phenylpyridines
datasetposted on 07.12.2011, 00:00 by Ourida Saidi, Jameel Marafie, Araminta E. W. Ledger, Po Man Liu, Mary F. Mahon, Gabriele Kociok-Köhn, Michael K. Whittlesey, Christopher G. Frost
A selective catalytic meta sulfonation of 2-phenylpyridines was found to occur in the presence of (arene)ruthenium(II) complexes upon reaction with sulfonyl chlorides. The 2-pyridyl group facilitates the formation of a stable Ru–Caryl σ bond that induces a strong para-directing effect. Electrophilic aromatic substitution proceeds with the sulfonyl chloride to furnish a sulfone at the position meta to the chelating group. This new catalytic process offers access to atypical regioselectivity for reactions involving chelation-assisted cyclometalation.