200072-19-1Relevant articles and documents
Study of the evolution of η1-η2-enylpalladium complexes when the palladium-migration process is blocked
Albéniz, Ana C.,Espinet, Pablo,Lin, Yong-Shou
, p. 5964 - 5973 (2008/10/08)
η1-η2-Enylpalladium complexes have been detected and/or isolated in the reaction of [PdPfBr(NCMe)2] (Pf = C6F5) with the dienes R-CH=CH-(CH2)n-Y-(CH2)m-CH=CH 2 (R = H, Me; n, m = 0, 1; Y = CCl2, C(COOMe)2, CO2, O, SiMe2, SO2). Insertion of one double bond into the Pd-aryl bond and coordination of the remaining double bond gives the above-mentioned organometallic derivatives. The dienes tested have a non-hydrogen-containing link (Y), so Pd migration to give η3-allyl derivatives is blocked. The evolution and decomposition processes observed for the η1-η2-enyls reveal that β-X elimination is the main operating pathway for Y = CCl2 (X = Cl) or Y = OCO, O, SiMe2 (X = YR′). When Y = C(COOMe)2 or SO2, C-X cleavage is not observed and intramolecular insertion to give cyclic products or Pd-H elimination to generate a substituted diene predominates, respectively. From these results, a trend in C-X cleavage easiness in the presence of palladium can be estimated: C-C ? C-SO2 C-Cl C-O (ether) C-O (ester) ≈ C-Si.
