3,3-Disubstitutedoxindoles are important structure motifs in natural products and pharmaceutical agents. Here we disclose a simple and direct access to this class of molecules by using readily available formaldehyde and isatins (and their imines) as the substrates. The reaction proceeds with the assistance of microwave heating in the presence of a mild base. Formaldehyde behaves as both a reductant
Synthesis of 3-Amino-3-hydroxymethyloxindoles and 3-Hydroxy-3-hydroxymethyloxindoles by Rh<sub>2</sub>(OAc)<sub>4</sub>-Catalyzed Three-Component Reactions of 3-Diazooxindoles with Formaldehyde and Anilines or Water
作者:Chengjin Wang、Dong Xing、Dongwei Wang、Xiang Wu、Wenhao Hu
DOI:10.1021/jo500307n
日期:2014.5.2
Efficient Rh(II)-catalyzed three-component reactions of 3-diazooxindoles and formaldehyde with either anilines or water were developed to give a series of substituted 3-amino-3-hydroxymethyloxindoles or 3-hydroxy-3-hydroxymethyloxindoles in good to excellent yields. In this atom- and step-economic transformation, Rh-2(OAc)(4)-catalyzed decomposition of 3-diazooxindoles with anilines or water forms the corresponding active ammonium or oxonium ylides. Electrophilic trapping of the resulting ammonium ylides or oxonium ylides by formaldehyde in the form of formalin efficiently produces the title compounds in one step.