The first stepwise syntheses of unsymmetrically substituted 1 ,I 9-dibromo-a,c-biladienes, e.g. 3c, via the so-called tripyrrene route', and their facile conversion into biliverdins (bilin-I ,I 9-diones), e.g. 4c, are described; this methodology is also adapted for the preparation of symmetrical biliverdins 4a, as well as corroles 5 and azaporphyrins 6.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.