Preparation of 2,3-disubstituted indoles from indole-3-carboxylic acids and amides by α-deprotonation

Abstract

Direct deprotonations have been used to obtain the 2(α)-lithiated indole-3-carboxylate dianions 8 and 14, together with the related 2(α)-lithiated indole-3-carboxamide monoanions 18 and 20b from the parent compounds. These four intermediates are useful for the preparation of 2.3-disubstituted indoles, especially by condensations with aldehydes and ketones and by alkylations using primary alkyl iodides.