Metallabenzenes and valence isomers. 3. Unexpected rearrangement of two regioisomeric iridabenzenes to an (eta(5)-cyclopentadienyl)iridium(I) complex

摘要

The reaction of (Z)-1-phenyl-2-(trimethylsilyl)-3-(2-lithiovinyl)cyclopropene (4) with Vaska's complex generates the iridabenzvalene 8, the iridabenzene 9, and the cyclopentadienyl complex 10 in a 10:2:3 ratio. Heating this mixture to 75 degreesC converts 8 and 9 to 10. NMR studies over a 24 h period at 75 degreesC show that samples containing pure 8 isomerize to 10 in high yield and generate regioisomeric iridabenzene 11 as an intermediate. [References: 29]