Ten Years of Glory in the α-Functionalizations of Acetophenones: Progress Through Kornblum Oxidation and C–H Functionalization

This review article focuses on the α-functionalization of acetophenones involving Kornblum oxidation and C–H functionalizations. Although various other strategies, such as classical approaches, enamine approaches and umpolung strategy are also known for this functionalization, here we discuss mainly the Kornblum oxidation approach and C–H functionalization strategy as they have advantages over the others. In Kornblum oxidation, the reaction uses iodine and dimethylsulfoxide and proceeds through the formation of arylglyoxal as the key intermediate. In C–H functionalization, the reaction requires metal, or metal-free catalyst, and generates radical intermediate in most cases. α-Functionalization of acetophenones is very important because of their huge applications in the synthesis of various natural products and pharmaceuticals and, therefore, a number of research articles have been published in this area. However, no review articles are available so far. In this article, we present a succinct discussion of various important and novel reactions, along with their mechanisms, published since 2012 to date. We believe that this first review article in this field will give readers one-stop information on this topic and encourage further intriguing work in this area.