In the presence of a mesoporous aluminosilicate Al-MCM-41, aldolreaction of various silyl enol ethers with both aromatic and aliphatic aldehydes proceeded under mild reaction conditions to afford the corresponding O-silylated aldol adducts in high yields. The solid acid catalyst was easily recovered and reusable three times.
A new synthetic procedure for the practical synthesis of β-trimethylsiloxyketones from silyl enol ethers and aldehydes has been described which heavily depends on organoaluminum reagent as an effective catalyst.
A cationic iridium complex [Ir(cod)2]SbF6 was found to be a new and efficient Lewis acid catalyst for Mukaiyama aldol and Mannich reactions. Aldehydes react smoothly with silyl enol ethers to give β-siloxy ketones in the presence of 0.5 mol % of [Ir(cod)2]SbF6. The reaction of N-alkyl arylaldimines with ketene silyl acetals in the presence of 5 mol % [Ir(cod)2]SbF6/P(OPh)3 gave β-amino esters. After
Homogeneous catalysis. A transition metal based catalyst for the Mukaiyama crossed-aldol reaction and catalyst deactivation by electron transfer.
作者:William Odenkirk、John Whelan、B. Bosnich
DOI:10.1016/0040-4039(92)89017-7
日期:1992.9
The cationic complex [Ru(salen)(NO)H2O]SbF6 is intrinsically a powerful catalyst for the Mukaiyama crossed-aldol reaction at 25°C in nitromethane solutions and at very low catalyst loadings but, for some reactions, electron transferfrom the silylenolether to the ruthenium catalyst can occur which leads to catalyst deactivation.
Homogeneous catalysis. [TiCp2(CF3SO3)2] and [ZrCp2(CF3SO3)2THF], fast and efficient catalysts for the Mukaiyama cross-aldol reaction
作者:T.Keith Hollis、N.P. Robinson、B. Bosnich
DOI:10.1016/s0040-4039(00)79005-8
日期:1992.10
The catalysts [TiCp2(CF3SO3)2] and [ZrCP2(CF3SO3)2THF] are fast and efficient catalysts for the Mukaiyama cross-aldol reaction involving both ketones and aldehydes and the catalysis is promoted by binding of the carbonyl group to the metal after dissociation of triflato ligands.