ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Synthesis of novel pregnane-based 20-carboxamides via palladium-catalysed aminocarbonylation

Gábor Mikle, Alexandra Zugó, Erzsébet Szatnik, Anita Maxim, Sándor Mahó, and László Kollár

Department of Inorganic Chemistry, Faculty of Sciences, University of Pécs, Pecs, Hungary

E-mail: miklegabor8@gmail.com

Received: 22 July 2020  Accepted: 16 December 2020

Abstract:

20-Carboxamidopregnene derivatives, such as 3β-acetoxy-5α-pregn-20-ene-20-carboxamides and 5α-pregn-20-ene-20-carboxamides were synthesized from the widely accessible 3β-acetoxy-pregn-5,16-dien-20-one (PDA) using selective hydrogenation, hydrazine and iodoalkene formation, as well as palladium-catalysed aminocarbonylation. The 20-iodo-20-ene derivatives, obtained from the corresponding 20-keto derivatives via their hydrazones, served as substrates. 23 new 20-carboxamides were obtained using various N-nucleophiles ranging from simple primary amines to α-amino acid esters. The novelty of this methodology lies in the application of facile, moderate or high-yielding reactions to obtain otherwise hardly accessible steroidal 20-carboxamides of pharmaceutical importance. In other words, instead of the enzymatic or synthetic degradation of e.g., sterols or cholanic acids, functionalization of the basic skeleton (a ‘building-up’ approach) was used.

Keywords: Iodoalkene; Carboxamide; Pregnane; Palladium; Aminocarbonylation

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-020-01478-7

Chemical Papers 75 (5) 1861–1867 (2021)