Abstract
Complexation of an arene to a low-valent metal carbonyl, such as Cr(CO)3, transfers electron density from the aromatic ring to the metal tricarbonyl moiety. As a result, the acidity of the aromatic ring as well as of the benzylic position is enhanced. Recently, several groups have developed catalytic reactions using a (π-arene)chromium complex, which is enhanced the reactivity of the arene by complexation.
