Diethyl 2,4-Dimethyl-5-[(triisopropylsilyl)methylene]-1,3-cyclopentadiene-1,3-dicarboxylate (cis- and trans- mixture)

To an ethanol (4.0 mL) solution of RhCl₃・xH₂O (3.81 mmol Rh) is added an ethanol (6.0 mL) solution of Cp^E precursor (1.55 mg, 3.81 mmol), and the mixture is stirred at 80 °C for 16 h. The resulting solution is concentrated under reduced pressure. The residue is diluted with CH₂Cl₂ (40 mL) and filtered. The filtrate is poured into hexane (200 mL). The resulting precipitates are collected, washed with Et₂O (20 mL) twice, and dried under vacuum to give Cp^E rhodium complex as a red powder; yield: 1.30 g (1.53 mmol, 80%).