α-Nitroarylation of Ketones and Esters: An Exceptionally Facile Synthesis of Indoles, 2-Indolinones, and Arylacetic Acids

Article abstract of DOI:10.1021/jo00360a014

Silyl enol ethers and ketene silyl acetals add to aromatic nitro compounds in the presence of fluoride ion sources to give dihydroaromatic nitronates which are readily oxidized to α-nitroaryl carbonyl compounds by DDQ or Br2.These versatile intermediates are readily converted into indoles or 2-indolinones by reductive cyclization.Since halogen substituents on the aromatic ring are not displaced in the initial alkylation reaction, nucleophilic substitution of these groups, followed by functional group manipulations of the nitro group, permits easy access to indoles, 2-indolinones, and arylacetic acids with varied substitution patterns.