Asymmetric Total Synthesis of Iheyamine B

Marine natural products

Covering: January to the end of December 2022This review covers the literature published in 2022 for marine natural products (MNPs), with 645 citations (633 for the period January to December 2022) referring to compounds isolated from marine microorganisms and phytoplankton, green, brown and red algae, sponges, cnidarians, bryozoans, molluscs, tunicates, echinoderms, the submerged parts of mangroves and other intertidal plants. The emphasis is on new compounds (1417 in 384 papers for 2022), together with the relevant biological activities, source organisms and country of origin. Pertinent reviews, biosynthetic studies, first syntheses, and syntheses that led to the revision of structures or stereochemistries, have been included. An analysis of NP structure class diversity in relation to biota source and biome is discussed.

Synthesis of 2-(2-nitrophenyl)indoline-3-acetic acid derivatives via base-catalyzed cyclization of N-(2-nitrobenzyl)-2-aminocinnamic acid derivatives

A protocol for the synthesis of 2-(2-nitrophenyl)indoline-3-acetic acid derivatives was developed via base-catalyzed cyclization of N-(2-nitrobenzyl)-2-aminocinnamic acid derivatives. The synthetic utility of this methodology was illustrated by the concise synthesis of dihydropaullone, a partially saturated analog of paullone. Furthermore, the indoline scaffold could be further converted to the corresponding indoles and other indole-fused heterocycles.

Total Syntheses of Iheyamines A and B

An efficient synthetic route to iheyamine A and its analogues was discovered; the crucial one-pot transformation included a C-C migration to form the characteristic seven-membered ring. Subsequent addition of acetone to iheyamine A initiated a cascade process to complete the total synthesis of iheyamine B.