Urea Activation of α-Nitrodiazoesters: An Organocatalytic Approach to N–H Insertion Reactions

The combination of a urea catalyst and an α-nitro-α-diazo ester gives rise to a reactive species able to undergo insertion into the N–H bonds of anilines. This new strategy to achieve N–H insertion reactivity is in contrast to typical metal-catalyzed conditions for the generation of carbenoids from α-diazocarbonyl compounds. This report includes the extension of the insertion reaction to a three-component coupling for the construction of α-amino-α-aryl esters in high yield.