Gold-catalyzed transformations of alpha-diazocarbonyl compounds: selectivity and diversity

Metal carbenes, generated from the decomposition of diazo compounds by transition-metals, have a broad range of applications in organic synthesis. The progress of organic transformation via transition metal (such as Rh, Cu, Fe, Ag) carbenes has been well summarized in a few excellent reviews. This review will summarize gold-catalyzed transformations of alpha-diazocarbonyl compounds by highlighting the specificity and applicability of these diverse transformations such as X-H insertion, C-H functionalization, cyclopropanation, cycloaddition, and coupling reactions. In order to understand these reactions, the mechanistic rationale for selected examples is also provided.