Study On The Chlorooxidation Of Indoles

The main part of this paper is divided into three parts.In the first part,the synthesis and application of 3-chlorooxindole and 3,3-dichlorooxindole compounds in many natural products and pharmaceuticals have been described.Many types of synthetic strategies to construct 3-chlorooxindole and 3,3-dichlorooxindole framework were summarized in the second part,different synthetic methods were compared and their characteristics were analyzed respectively.In the third part,we have developed a novel methodology to build 3-chlorooxindole and 3,3-dichlorooxindole skeleton using indoles and their derivatives.This method can be used to synthesize target products with high efficiency and moderation.When DMF and trifluoroacetic acid mixing system were used as the solvent,the yield of N-alkyl substituted 3-chlorooxindoles could reach 92%,and the system could be extended to indoles.The yield of 3,3-dichlorohydroxyindole compounds were obtained in 99%yields by using 1,4-dioxane as solvent,and the reaction could be extended to heterocyclic compounds.Inexpensive hypervalent iodine reagents instead of those highly reactive oxidants were used in our strategy for synthesis of 3-chlorooxindole and 3,3-dichlorooxindole compounds.In a similar manner,the 3,3-dichloro and 3-chlorooxindole derivatives could be obtained by the reaction of the indole with hypervalent iodine reagents in the presence of water.On the basis of control experiments and literature precedents,a plausible mechanism for the reaction was proposed.Finally,with the optimized conditions in hand,different substrates were tested for the synthesis of 3-chlorooxindole and 3,3-dichlorooxindole compounds.