Total Synthesis of the Cytostatic Marine Natural Product Dibromophakellstatin via Three-Component Imidazolidinone Anellation Michael Zöllinger Peter Mayer Thomas Lindel 10.1021/jo061813u.s008 https://acs.figshare.com/articles/dataset/Total_Synthesis_of_the_Cytostatic_Marine_Natural_Product_Dibromophakellstatin_via_Three_Component_Imidazolidinone_Anellation/3042796 The tetracyclic pyrrole−imidazole alkaloid dibromophakellstatin from the marine sponge <i>Phakellia </i><i>mauritiana</i> has been synthesized within seven steps from pyrrole in an 18% overall yield. The key step is a three-component assembly of a tricyclic enamide, a nitrene, and a carbamoyl building block, affording the imidazolidinone ring of dibromophakellstatin in one step. Notably, it is possible to employ the reagent EtO<sub>2</sub>CNHOTs in a double function as a source of the electrophilic nitrene and of a dipolar carbamoyl component. Use of debrominated precursor dipyrrolopyrazinones leads to much higher anellation yields and allowed us to develop a second generation synthesis. The cytostatic activity of dibromophakellstatin is confirmed. 2006-12-08 00:00:00 dipolar carbamoyl component Cytostatic Marine Natural Product Dibromophakellstatin pyrrole marine sponge Phakellia mauritiana electrophilic nitrene generation synthesis anellation yields reagent EtO 2CNHOTs imidazolidinone ring carbamoyl building block dibromophakellstatin cytostatic activity debrominated precursor dipyrrolopyrazinones Total Synthesis tricyclic enamide