Construction of Substituted N-Hydroxyindoles

Significance

A new route to the construction of 2,3-substituted N-hydroxyindoles from simple nitrobenzene derivatives is reported. The reaction proceeds by partial and selective reduction of a nitro bromobenzene derivative followed by intramolecular cyclization-dehydration, and an interesting nucleophilic addition to give products in modest to good yields. Various nucleophiles, Nu = AlkOH, AlkSH, Alk₂NH, ArNH₂, ArH may be used. One of the N-hydroxyindole products was used in the construction of nocathiacin I, isolated from Nocardia sp. and the fungus Amicolaptosis sp., showing in vitro and in vivo activity against Gram-positive bacteria.