First C−H Activation Route to Oxindoles using Copper Catalysis
作者:Johannes E. M. N. Klein、Alexis Perry、David S. Pugh、Richard J. K. Taylor
DOI:10.1021/ol1012668
日期:2010.8.6
The preparation of 3,3-disubstituted oxindoles by a formal C-H, Ar-H coupling of anilides is described. Highly efficient conditions have been Identified using catalytic (5 mol %) Cu(OAc)(2)center dot H(2)O with atmospheric oxygen as the reoxidant; no additional base is required, and the reaction can be run in toluene or mesitylene. Optimization studies are reported together with a scope and limitation investigation based on variation of the anilide precursors. The application of this methodology to prepare a key Intermediate for the total synthesis of the anticancer, analgesic oxindole alkaloid Horsfiline is also described.
Intramolecular Dehydrogenative Coupling Approach to 2‐Oxindoles Using Fe(OAc)
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A novel method for the synthesis of 2‐oxindoles from 1,3‐dicarbonyl compounds based on ferrous salt and iodide catalyst was described. Through a new catalytic oxidation system, the intramolecular dehydrogenation coupling reaction was completed by using catalytic amount of iodine.