A Rh(II)- or Ag(I)-Catalyzed Formal C-O Bond Insertion of Cyclic Hemiaminal with Aryl Diazoacetate

A mild and facile synthetic method via convergent assembly of two reactive intermediates generated in situ has been developed. This method provides an efficient way to construct six- and seven-membered N-heterocycles containing a biaryl linkage. This reaction features a gem-difunctionalization process of diazo compounds with cyclic hemiaminals, delivering alpha-hydroxyl-beta-amino ester derivatives with a tertiary carbon center through a formal C-O bond-insertion transformation.