Synthetic studies towards conocurvone: A novel synthesis of trimeric quinone via the first reactions of carbene complex with conjugated triynes

The first benzannulation reactions of Fischer carbene complexes and conjugated triynes have been investigated. The extraordinary chemoselectivity of the benzannulation reactions of substituted triynes with cyclohexenyl carbene complex and phenyl carbene complex has been reported. The first benzannulation reaction of cyclohexenyl carbene complex with triisopropylsilyl-substituted triyne has exclusively taken place in the internal alkyne position, while the first benzannulation reaction of aryl- and adamantyl-substituted triynes with cyclohexenyl carbene complex takes place in the external alkyne position. In the effort to explain all the experimental results, the mechanism of this reaction has also proposed. This methodology has also applied to the synthesis of the trimeric quinone, which is the core carbon framework of natural product Conocurvone.; In the second part, a new potential tetra-dentate ligand (DIMON) has been synthesized in an asymmetric version. This ligand will be applied to the asymmetric reactions in the future studies.