During our research on the reactivity of α-diazo esters 1, which are easily prepared from various α-amino acid esters, 6, 6a and 6b we reported a modified synthesis method for polysubstituted indoles by combining the classical Fischer reaction with our new reaction: the facile formation of arylhydrazones by the coupling of 1 and various arylmetal reagents. 7, 7a and 7b Fischer indole synthesis was well known to involve a 3,3-sigmatropic rearrangement of hydrazine ...
