Regioselective Radical Arylation of 3-Hydroxypyridines.
The titanium(III)-mediated radical arylation of 3-hydroxypyridines was found to proceed with high regioselectivity for the 2-position. Using aryldiazonium chlorides, which were prepared from the corresponding anilines, as aryl radical sources, a range of 3-hydroxy-2-phenylpyridines were obtained in moderate to good yields under simple reaction conditions. Reactions of ortho-carboxylic ester substituted phenyldiazonium salts directly provided tricyclic benzopyranopyridinones.
Department of Chemistry and Pharmacy, Pharmaceutical Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg , Schuhstraße 19, 91052 Erlangen, Germany.
Michael C D
MC
Fürst
Department of Chemistry and Pharmacy, Pharmaceutical Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg , Schuhstraße 19, 91052 Erlangen, Germany.
Leonard R
LR
Bock
Department of Chemistry and Pharmacy, Pharmaceutical Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg , Schuhstraße 19, 91052 Erlangen, Germany.
Markus R
MR
Heinrich