The two chapters in Volume 83 describe reactions that represent two major (and growing) franchises in the Organic Reactions series, namely, transition metal catalyzed cross-coupling reactions and multicomponent reactions. These two processes not only have a rich history in synthetic organic chemistry, but also represent some of the most commonly employed transformations in the modern practice of molecule construction. The first chapter authored by Eiichi Nakamura, Takuji Hatakeyama, Shingo Ito, Kentaro Ishizuka, Laurean Ilies, and Masaharu Nakamura describes one of the most exiting advances in the field of transition metal catalyzed cross-coupling reactions: the use of iron catalysts. The second ... Read morechapter authored by Stephen G. Pyne and Minyan Tang describes the latest in a long line of multicomponent reactions published in this series: the boronic acid Mannich reaction, sometimes called the Petasis reaction.