10. [CpRu]-Catalyzed Carbene Insertions into Epoxides: 1,4-Dioxene Synthesis through S_N1-Like Chemistry with Retention of Configuration
    Achard, T.; Tortoreto, C.; Poblador-Bahamonde, A. I.; Guénée, L.; Bürgi, T.; Lacour, J.
    Angew. Chem. Int. Ed. 2014, 53, 6140-6144

Rather than lead to the usual deoxygenation pathway, metal carbenes derived from α-diazo-β-ketoesters undergo three-atom insertions into epoxides using a combination of 1,10-phenanthroline and [CpRu(CH₃CN)₃][BAr_F] as the catalyst. Original 1,4-dioxene motifs are obtained as single regio- and stereoisomers. A perfect syn stereochemistry (retention, e.r. up to 97:3) is observed for the ring opening, which behaves as an S_N1-like transformation.

DOI: 10.1002/anie.201402994 

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