798542-59-3Relevant articles and documents
C-C and C-H bond activation of dialkylmethylenecyclopropane promoted by rhodium and iridium complexes. Preparation and structures of M(η1:η2-CH2CR2CH=CH 2)(CO)(PPh3)2 and trans-M(CH=CHCMeR 2)(CO)(PPh3)2 (M = Rh, Ir, R = CH 2CH2Ph)
Itazaki, Masumi,Yoda, Chikako,Nishihara, Yasushi,Osakada, Kohtaro
, p. 5402 - 5409 (2008/10/09)
2,2-Bis(2-phenylethyl)-1-methylenecyclopropane reacts with RhH(CO)(PPh 3)3 at room temperature and with IrH(CO)(PPh 3)3 at 70°C to form the 3-butenyl complexes of these metals, M{η1:η2-CH2C(CH 2CH2Ph)2CH=CH2}(CO)(PPh 3)2 (1, M = Rh; 2, M = Ir). Heating 1 at 55°C liberates 1,1-bis(2-phenylethyl)-1,3-butadiene, while the thermal reaction of 2 at 110°C forms a mixture of 3-methyl-3-vinyl-1,5-diphenyl-1-pentene (48% NMR yield) and 3-methyl-3-vinyl-1,5-diphenylpentane (15% NMR yield). The reactions of excess amounts of 2,2-bis(2-phenylethyl)-1-methylenecyclopropane with RhH(CO)(PPh3)3 at 55°C and with IrH-(CO)(PPh 3)3 at 115°C afford the alkenyl complexes trans-Rh{(Z)-CH=CHC(CH2CH2Ph)2CH 3}-(CO)(PPh3)2 (3) and trans-Ir{(E)-CH= CHC(CH2CH2Ph)2CH3}(CO)(PPh 3)2 (4), respectively. The reaction mechanisms are discussed on the basis of the results of the reactions under different conditions. HC≡CC(CH2CH2Ph)2CH 3 reacts with MH(CO)(PPh3)3 (M = Rh, Ir) to afford the alkynyl complexes trans-M{C≡CC(CH2CH 2Ph)2CH3}(CO)(PPh3)2 (5, M = Rh; 6, M = Ir) via oxidative addition of the C(alkyne)-H bond to the metal center and subsequent elimination of H2.