Rasappan, Ramesh and Hager, Markus and Gissibl, Anja and Reiser, Oliver (2006) Highly Enantioselective Michael Additions of Indole to Benzylidene Malonate Using Simple Bis(oxazoline) Ligands: Importance of Metal/Ligand Ratio. Organic Letters 8 (26), pp. 6099-6102.
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Simple bis(oxazoline) ligands, especially azabis(oxazolines), can catalyze the copper-catalyzed addition of indoles to benzylidene malonates in up to >99% ee, provided that excess of chiral ligand is avoided. The paradigm followed in many asymmetric catalyses that an excess of chiral ligand with respect to the metal should improve enantioselectivity because a background reaction by free metal is suppressed, is not applicable here, which might call for revisiting some of the many copper(II)-bis(oxazoline)-catalyzed processes known.
|Institutions:||Chemistry and Pharmacy > Institut für Organische Chemie > Lehrstuhl Prof. Dr. Oliver Reiser|
|Subjects:||500 Science > 540 Chemistry & allied sciences|
|Refereed:||Yes, this version has been refereed|
|Created at the University of Regensburg:||Yes|
|Deposited On:||18 Oct 2007|
|Last Modified:||20 Jul 2011 21:11|