Ring construction nine-membered rings from

The intramolecular nucleophilic attack of a nitrogen atom on an allylpalladium complex was also used to construct a five and a six membered heterocycle in the same step. TV-substituted 2-iodobenzamides bearing an allene function in the appropriate distance from the iodine underwent cyclization through the carbopalladation of the allene moiety by the arylpalladium complex, formed in the first step of the catalytic cycle. The intermediate allylpalladium complex, part of a nine membered ring, cyclized readily to give the pyrroloisoquinolone derivative in excellent yield (4.23.). The nature of the added ligand and the solvent both had a marked influence on the efficiency of the transformation.26... 

Before constructing the nine-membered ring amine of fawcettimine 3, it was first necessary to protect the ketone as the ketal. Pd-mediated coupling of the alkenyl iodide with the organoborane derived from 11 then proceeded smoothly, as did the subsequent hydrobora-tion of the terminal alkene. 

The formation of a nine-membered ring system through alkene RCM also proved to be challenging [46]. In 2008, Hoppe et al. reported the asymmetric total synthesis of (+)-vigulariol (29), a cytotoxic and tetracyclic diterpene which was isolated from the sea pen Vigularia juncea (Fig. 10) [49]. The key step in this total synthesis involves the construction of the oxacyclononene framework by... 

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