<i>N</i>- and <i>O</i>-arylation of pyridin-2-ones with diaryliodonium salts: base-dependent orthogonal selectivity under metal-free conditions

Abstract

Metal-free <i>N</i>- and <i>O</i>-arylation reactions of pyridin-2-ones as ambident nucleophiles have been achieved with diaryliodonium salts on the basis of base-dependent chemoselectivity. In the presence of <i>N</i>,<i>N</i>-diethylaniline in fluorobenzene, pyridin-2-ones were very selectively converted to <i>N</i>-arylated products in high yields. On the other hand, the <i>O</i>-arylation reactions smoothly proceeded with the use of quinoline in chlorobenzene, leading to high yields and selectivities. In these methods, a variety of pyridin-2-ones in addition to pyridin-4-one and a set of diaryliodonium salts were accepted as suitable reaction partners.