Affiliation:
1. Department of Chemistry Korea University 145 Anam-ro, Seongbuk-gu Seoul 02841 Republic of Korea (YHL), (CHC
Abstract
AbstractThis perspective article describes the recent progress in the total syntheses of iheyamines A and B. Since iheyamine A possesses a highly unique unsymmetrical azepino‐2,2’‐bisindole scaffold, novel strategies to construct the basic scaffold have been developed, and unique total syntheses have been reported based on these strategies. In addition, because iheyamine B bears vicinal 2‐oxopropyl moieties with a trans‐configuration in the azepine scaffold of iheyamine A, the first asymmetric total synthesis of iheyamine B took a substantially longer time than iheyamine A to complete. Due to the unusual structure of iheyamine B and some discrepancies in the experimental data between the isolated and synthesized iheyamine B, some controversial issues regarding whether iheyamine B is a natural product or an artifact have been raised and will be discussed.
Reference40 articles.
1. Iheyamines, new cytotoxic bisindole pigments from a colonial ascidian, Polycitorella sp.
2. “Unsymmetrical 2 2’-bisindole moiety” refers to a 2 2’-bisindole scaffold bearing a different substituent(s) on each phenyl ring of the indole scaffold regardless of the substituent(s) on the pyrrole ring of the indole rings. Because iheyamines A (1) and B (2) have one methoxy group on only one of the phenyl rings in the 2 2’-bisindole scaffold we considered that they possess an unsymmetrical 2 2’-bisindole moiety.
3. 2,2′-Biindolyl revisited. Synthesis and reactions
4. It has been reported that only 7.0 mg of iheyamine A (1) and 3.3 mg of iheyamine B (2) were obtained from a 1.2 kg sample of purple ascidian. For details see ref 1.
5. A Compact Approach to an Isomeric Iheyamine A System and X-ray Crystal Structure of 5-Methyl-5H-azepino[2,3- b :4,5- b ′]diindole