TY - JOUR T1 - Scope and mechanism of the intermolecular addition of aromatic aldehydes to olefins catalyzed by Rh(I) olefin complexes. AU - Roy,Amy H, AU - Lenges,Christian P, AU - Brookhart,Maurice, Y1 - 2007/01/31/ PY - 2007/2/1/pubmed PY - 2007/3/29/medline PY - 2007/2/1/entrez SP - 2082 EP - 93 JF - Journal of the American Chemical Society JO - J Am Chem Soc VL - 129 IS - 7 N2 - Rhodium (I) bis-olefin complexes Cp*Rh(VTMS)(2) and CpRh(VTMS)(2) (Cp* = C(5)Me(5), Cp = C(5)Me(4)CF(3), VTMS = vinyl trimethylsilane) were found to catalyze the addition of aromatic aldehydes to olefins to form ketones. Use of the more electron-deficient catalyst CpRh(VTMS)(2) results in faster reaction rates, better selectivity for linear ketone products from alpha-olefins, and broader reaction scope. NMR studies of the hydroacylation of vinyltrimethylsilane showed that the starting Rh(I) bis-olefin complexes and the corresponding Cp*/Rh(CH(2)CH(2)SiMe(3))(CO)(Ar) complexes were catalyst resting states, with an equilibrium established between them prior to turnover. Mechanistic studies suggested that CpRh(VTMS)(2) displayed a faster turnover frequency (relative to Cp*Rh(VTMS)(2)) because of an increase in the rate of reductive elimination, the turnover-limiting step, from the more electron-deficient metal center of CpRh(VTMS)(2). Reaction of Cp*/Rh(CH(2)CH(2)SiMe(3))(CO)(Ar) with PMe(3) yields acyl complexes Cp*/Rh[C(O)CH(2)CH(2)SiMe(3)](PMe(3))(Ar); measured first-order rates of reductive elimination of ketone from these Rh(III) complexes established that the Cp ligand accelerates this process relative to the Cp* ligand. SN - 0002-7863 UR - https://www.unboundmedicine.com/medline/citation/17263531/Scope_and_mechanism_of_the_intermolecular_addition_of_aromatic_aldehydes_to_olefins_catalyzed_by_Rh_I__olefin_complexes_ L2 - https://doi.org/10.1021/ja066509x DB - PRIME DP - Unbound Medicine ER -