Brønsted Acid Catalyzed Cyclization of Aminodiazoesters with Aldehydes to 3-Carboxylate-N-Heterocycles

A Bronsted acid catalyzed cyclization of aminodiazoesters with aldehydes is described. This reaction features broad substrate generality and functional group compatibility, affording a wide range of 5–7-membered 3-carboxylate-N-heterocycles containing different functional groups. The title products are able to be further elaborated through simple functional group transformations to produce synthetically useful N-heterocycles.