Hydrazones as organometallic equivalents in cross-coupling reactions

Abstract

While transition-metal-catalyzed cross-coupling reactions are among the most important tools in modern organic synthesis; however, they rely on preformed organometallic reagents, which often require multistep preparation, exhibit air and moisture sensitivity, and generate stoichiometric metal halide waste. To address these limitations, our laboratory has developed HOME (Hydrazones as Organo-Metallic Equivalents) chemistry. Through hydrazine-mediated umpolung activation, abundant oxygenated hydroxyl and carbonyl feedstocks function as organometallic equivalents in transition-metal-catalyzed cross-coupling reactions. This approach eliminates the need for preformed organometallic reagents, demonstrates broad functional-group tolerance, and produces only benign nitrogen gas as the stoichiometric byproduct. By improving operational simplicity, using renewable resources and reducing waste, HOME chemistry provides a practical and more sustainable alternative to conventional cross-coupling methodologies.