Mild Microwave-Assisted Synthesis of Dipyrromethanes and Their Analogues
作者:K. Borbas、Ruisheng Xiong
DOI:10.1055/s-0034-1378925
日期:——
The Mannich reaction between pyrroles or indoles and Eschenmoser's salt (dimethylmethylideneammonium iodide) forms N,N-dimethylamino-methylated derivatives in good to excellent yields. The reaction is highly regioselective, and for pyrroles both 2- and 3-substituted derivatives could be obtained. The N,N-dimethylaminomethylpyrroles and indoles underwent substitution with pyrrole under microwave irradiation, affording the appropriate dipyrromethanes, N-confused, and indolo-dipyrromethanes in moderate to excellent overall yield.
Preparation and Characterization of Aryl or Heteroaryl(3-indolyl)methylium <i>o</i>-Benzenedisulfonimides
An initial study has been accomplished into the synthetic feasibility of the preparation of diarylcarbenium salt via the direct coupling of aryl (or heteroaryl) aldehydes and arenes (or heteroaryl analogues) in the presence of a strong organic Brønsted acid. A number of stabilized aryl or heteroaryl(3-indolyl)carbenium ions, never previously prepared in the solid state, have been isolated in excellent