α-Ketoglutaric acid in Ugi reactions and Ugi/aza-Wittig tandem reactions

TL;DR

This paper describes the synthesis of bis- and tetraamides using α-ketoglutaric acid in Ugi reactions, with some products forming quinoxalinone-containing compounds via a tandem Ugi/aza-Wittig process.

Contribution

The novel contribution is the successful one-pot tandem Ugi/aza-Wittig reaction using α-ketoglutaric acid to form substituted quinoxalinone derivatives.

Findings

Bis- and tetraamides were synthesized using α-ketoglutaric acid in Ugi reactions.

A tandem Ugi/aza-Wittig process produced substituted quinoxalinone derivatives with a pharmacophore moiety.

The tandem reaction was successfully carried out in a one-pot procedure without isolating intermediates.

Abstract

A small library of bis- and tetraamides was synthesized by the Ugi reaction with α-ketoglutaric acid, tert-butyl isocyanide, aromatic aldehydes, and aromatic amines. When o-azidoanilines were used, azidated peptidomimetics were obtained, the post-cyclization of which by the aza-Wittig reaction yielded a series of substituted 3-(3-oxo-3,4-dihydroquinoxalin-2-yl)propanoic acids containing a pharmacophore quinoxalinone moiety. The tandem Ugi/aza-Wittig combination was also carried out in a one-pot procedure without isolation of the intermediate.

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