Silylstannation of terminal alkynes using a recyclable palladium(0) catalyst immobilised in an ionic liquid
作者:Ivan Hemeon、Robert D. Singer
DOI:10.1039/b205999a
日期:2002.8.21
Silylstannanes can be regioselectively added across terminal alkynes in a quantitative fashion in the presence of a palladium(0) catalyst immobilised in the [bmim]PF6 ionic liquid which can be recycled without loss of activity.
highly enantioselective silicon-directed Nazarov reactions which were cooperatively catalyzed by a Lewis acid and a chiralBrønstedacid. The chiral cyclopentenones we synthesized using this method generally cannot be obtained by means of other catalytic enantioselective reactions, including previously reported methods for enantioselective Nazarov cyclization. The silicon group in the dienone substrate stabilized
Formation and reactions of olefins with vicinal silyl and stannyl substituents
作者:T. N. Mitchell、R. Wickenkamp、A. Amamria、R. Dicke、U. Schneider
DOI:10.1021/jo00231a009
日期:1987.10
Silylstannanes in organic synthesis. Scope and limitation of palladium-catalyzed reaction with acetylenes
作者:B. L. Chenard、C. M. Van Zyl
DOI:10.1021/jo00369a001
日期:1986.9
Recyclable palladium(0)-catalysed silylstannation of terminal alkynes in ionic liquids
作者:I Hemeon
DOI:10.1016/j.molcata.2003.09.032
日期:2004.5.18
The palladium(0)-catalysed addition of silylstannanes Bu3SnSiMe3 and Bu3SnSiMe2Ph to terminal alkynes has been shown to proceed in the ionic liquids 1-n-butyl-3-methylimidazolium hexafluorophosphate ([bmim]PF6) and 1-n-butyl-3-methylimidazolium tetrafluoroborate ([bmim]BF4). These reactions generally proceed in excellent yields to give 1-trialkylsilyl-2-tributylstannyl-1Z-alkenes regio- and stereoselectively as a single product with reaction times comparable to those reported for reactions performed in tetrahydrofuran (THF). The reaction has been shown to tolerate remote functionality on the alkyne. Each of the ionic liquids containing the immobilised palladium catalyst has been recycled up to 10 times without loss of activity, allowing extensive reuse of the expensive solvent/catalyst system. A catalyst activation stage involving mild heating of the palladium catalyst in the ionic liquid/diethyl ether solvent system decreased reaction time in the first cycle once all reagents were added, indicating the formation of a catalytically active palladium species other than tetrakis(triphenylphosphine)palladium(0). (C) 2004 Elsevier B.V. All rights reserved.