Efficient Synthesis of Biologically Interesting 3,4‐Diaryl‐Substituted Succinimides and Maleimides: Application of Iron‐Catalyzed Carbonylations

Abstract

A straightforward two-step synthesis of trans-3,4-disubstituted succinimides through a palladium-catalyzed Sonogashira reaction and an iron-catalyzed double carbonylation is described. In situ oxidative dehydrogenation gave the corresponding 3,4-diarylmaleimides. By starting from readily available aryl and heteroaryl halides, a variety of new analogues and derivatives of bioactive 3,4-bisindolylmaleimides are obtained in good yield and selectivity.

Iron‐Catalyzed Synthesis of Pyrrole Derivatives and Related Five‐Membered Azacycles

“…Beller's group reported an one‐pot method for the synthesis of various substituted succinimides 223 by means of [Fe(CO) 5 ] or [Fe 3 (CO) 12 ] catalyzed double carbonylation of alkynes and nucleophilic attack (both in intermolecular and intramolecular manners) starting from different terminal and internal alkynes 222 with ammonia or amines in 2009 (Scheme 34). [51] Later, potentially bioactive 3,4‐diaryl‐substituted succinimdes and maleimides were also synthesized [52] . Furthermore, this iron‐catalyzed carbonylation strategy was used as a key step in the short and efficient synthesis of Himanimide A and B [53] …”

3,4-Bis[1-(prop-2-ynyl)-1H-indol-3-yl]-1H-pyrrole-2,5-dione

“…Bisindolylmaleimides have been isolated from natural products (Kamata et al, 2006). The synthesis of bisindolylmaleimides (Prateeptongkum et al, 2010) and an example of a related crystal structure (Huang et al, 2012) have been reported.…”

1-Ethyl-2-phenyl-3-[2-(trimethylsilyl)ethynyl]-1H-indole

“…The synthesis and functionalization of indoles have been the object of research for over one and a half century (Shiri, 2012). Few examples of Sonogashira-type reactions on the indole core have been described (Hussain et al, 2011;Prateeptongkum et al, 2010).…”