Sunday, March 11, 2007

Synthesis of 1,2-Disubstituted Benzimidazoles by a Cu-Catalyzed Cascade Aryl Amination/Condensation Process


From: Prof. Dawei Ma's group at Shanghai Institute of Organic Chemistry, Shanghai, P.R. China

A new cascaded method in synthesizing 1,2-disubstitued benzimidazoles starting from 2-haloacetanilides, catalyzed by CuI/L-proline catalyst system. This is a copper-catalyzed amination process or aryl iodide or bromide, which attaches an primary amine to the aryl ring, followed by a ring closure of the 2-acetanilide group in one pot. The amination process is promoted by the ortho-NHCOR group in substrate since the simple amination of iodobenzene does not provide any amination product.

This is the kind of work which summarized results in tables speak better than words. So here they are.

For the aryl iodide substrates,
For the aryl bromide substrates,

The aryl bromide results are not ideal to view in this blog. For best viewing, look at the actual article.

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