Cyclization reactions of rhodium carbene complexes. Effect of composition and oxidation state of the metal

摘要

Treatment of o-(1,7-octadiynyl)benzoyldiazoethane with rhodium(II) octanoate in pentane resulted in a double internal/internal alkyne insertion reaction producing a labile bicyclo[4.1.0]hept-1(7)- ene derivative which readily undergoes a Diels-Alder reaction with diphenylisobenzofuran. Changing the solvent from pentane to CH_2CL2 afforded a 2:1 mixture of cis-and trans-alkenyl- Substituted indenones.