Synthetic aspects of the oxidative amidation of phenols

The oxidative amidation of phenols effects the conversion of appropriately substituted phenols into 4-amidodienones (‘para-oxidative amidation’) or 2-amidodienones (‘ortho-oxidative amidation’) by the action of hypervalent iodine reagents. The reagent, (diacetoxyiodo)benzene (‘DIB’) is especially effective in these transformations. This paper focuses on techniques for the desymmetrization of the dienoes thus obtained, leading to the stereocontrolled creation of N-substituted spiro carbons. The methodology creates new opportunities in alkaloid synthesis, as apparent from a number of examples.