155678-86-7Relevant academic research and scientific papers
Ring-methyl activation in pentamethylcyclopentadienyl complexes. 3. Synthesis and reactions of (η4-tetramethylfulvene) (η5-cyclopentadienyl)rhodium and -iridium
Gusev, Oleg V.,Sergeev, Sergei,Saez, Isabel M.,Maitlis, Peter M.
, p. 2059 - 2065 (2008/10/08)
[Rh(η5-C5Me5)(η5-C 5H5)]+ (1a) was deprotonated (by potassium tert-butoxide) to give the neutral tetramethylfulvene complex [Rh(η4-C5Me4:CH2)(η 5-C5H5)] (2a), which was a good nucleophile toward Me3SiCl, CH2=CHCH2Br, PhCH2Br, Cl2, I2, CO2 (+MeI), and Ph2CO, giving [Rh(η5-C5Me4CH2X)(η 5-C5H5)]+ (X = Me3Si-, CH2=CHCH2-, PhCH2-, Cl, I, MeO2C-, and Ph2C(OH)-, respectively). The complex 2a also yielded 1a both on protonation and on treatment with the ferrocenium ion in THF. Similar reactions were carried out on [Ir(η5-C5Me5)(η5-C 5H5)]+ (1b), deprotonated by lithium diisopropylamide in THF, yielding [Ir(η5-C5Me4CH2X)(η 5-C5H5)]+ (X = Me3Si-, PhCH2-, or Ph2C(OH)-) with Me3SiCl, PhCH2Br, or Ph2CO; these reactions presumably proceeded via [Ir(η4-C5Me4:CH2)(η 5-C5H5)] (2b). While both 2a and 2b reacted with MeI, 2a gave a mixture of complexes, [Rh(C5H5)(C5MenEt 5-n)]+ (7a, n = 1-5), whereas the iridium complex 2b gave just [Ir(η5-C5Me4Et)(η5-C 5H5)]+. Possible mechanisms for this process are reviewed.
