Chiral N-heterocyclic carbene ligands for asymmetric catalytic oxindole synthesis
作者:Yi-Xia Jia、J. Mikael Hillgren、Emma L. Watson、Stephen P. Marsden、E. Peter Kündig
DOI:10.1039/b810858g
日期:——
The Pd-catalysed asymmetric intramolecular alpha-arylation of amide enolates containing heteroatom substituents gives chiral 3-alkoxy or 3-aminooxindoles in high yield and with enantioselectivities up to 97% ee when a new chiralN-heterocycliccarbeneligand is used.
A robust, efficient catalyst system for enolate arylation leading to quaternary 3-aminooxindoles
作者:Emma L. Watson、Stephen P. Marsden、Steven A. Raw
DOI:10.1016/j.tetlet.2009.02.076
日期:2009.7
A catalyst screening programme has revealed that a combination of Pd(0) and the N-heterocyclic carbene ligand SIPr forms a particularly robust and efficient catalyst for the formation of important quaternary 3-aminooxindoles via intramolecular enolate arylation. Catalyst loadings of 0.1 mol % give complete conversion in under 4 h. (C) 2009 Elsevier Ltd. All rights reserved.