Stoichiometric alkyne cyclotrimerization at a ruthenium centre: A new synthetic route to Ru(η6-arene)(η4-cycloocta-1,5-diene) complexes
作者:Paolo Pertici、Alessandra Verrazzani、Giovanni Vitulli、Richard Baldwin、Martin A. Bennett
DOI:10.1016/s0022-328x(97)00425-7
日期:1998.1
Alkynes RC2R' [R = H, R' = Bu-n, CH2CMeEt, (CH2)(5)C2H; R = R' = Me, Ph; R = Me, R' = Pr-n] undergo stoichiometric cyclotrimerization on reaction with the naphthalene-ruthenium(0) complex Ru(eta(6)-C10H8)(eta(4)-C8H12), 1, at room temperature to give the corresponding Ru(eta(6)-arene)(eta 4-C8H12) complexes in moderate to excellent yield. Unsymmetrical alkynes give a mixture of the isomeric eta(6)-1,3,5-(a) and eta(6)-1,2,4-arene (b) complexes, the ratio a:b being dependent on the electronic and steric effects of R and R'. In the presence of 1, 1-hexyne and 4-methyl-1-hexyne cocyclotrimerize with acetonitrile to give substituted pyridines, which are formed in addition to the Ru(eta(6)-arene)(eta(4)-C8H12) complexes. (C) 1998 Elsevier Science S.A.