| Abstract
| - The rate constants of the oxidative addition of the transition-metal iodocyclopentadienyl complexes (η5-C5H4-I)MLn (MLn = Mn(CO)3 (1a), Re(CO)3 (1b), CpFe (1c)) with Pd0(PPh3)4 have been determined in DMF. As expected, the oxidative addition is faster for the electron-acceptor groups Mn(CO)3 and Re(CO)3 than for the electron-donor group FeCp, with the reactivity order 1a> 1b ≫ 1c.
- The rate constants of the oxidative addition of thetransition-metal iodocyclopentadienyl complexes (η5-C5H4-I)MLn (MLn = Mn(CO)3 (1a), Re(CO)3 (1b), CpFe (1c)) withPd0(PPh3)4 have been determined in DMF. As expected, theoxidative addition is faster for the electron-acceptor groups Mn(CO)3 and Re(CO)3 than for the electron-donor group FeCp,with the reactivity order 1a> 1b ≫ 1c. Comparison of therate constants of the oxidative additions affords a new strategyfor the evaluation of the electronic properties of transition-metal units ligated to the iodocyclopentadienyl moiety with thefollowing decreasing electron-acceptor properties: Mn(CO)3> Re(CO)3 ≫ FeCp. The complexes formed in the oxidativeaddition are characterized as trans-[(η5-C5H4)PdI(PPh3)2]MLn(MLn = Mn(CO)3 (2a), Re(CO)3 (2b), CpFe (2c)) with thedecreasing stability order in DMF: 2c ≫ 2b> 2a. Therelevance to the efficiency of palladium-catalyzed Stille orSonogashira reactions from related complexes 1 is discussed.
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