An application of the Nenitszescu reaction to the synthesis of 1,2-annulated indoles and Benz[g]indoles

Abstract

The Nenitszescu reaction has been investigated as a means of preparing several indoles, benz[g]-indoles and 1,2-annulated indoles (3),(9),(13),(17) and (18) and a number of their derivatives.Reactions between benzoquinone and enaminones to form Michael addition products (15) and (16), major intermediates in the Nenitszescu reaction, and the acetic acid induced cyclization of (16) to (22) are recorded. Attempts to produce functionalized 5-hydroxyindoles as possible precursors to the mitomycin structure are discussed.