- Asymmetric deprotonation of N-Boc-piperidines
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A selection of chiral ligands was screened for the asymmetric deprotonation of N-Boc-piperidine. The asymmetric deprotonation of this compound is notoriously difficult and reasonable yields are obtained only with non-hindered ligands, such as tetramethyle
- Coldham, Iain,O'Brien, Peter,Patel, Jignesh J.,Raimbault, Sophie,Sanderson, Adam J.,Stead, Darren,Whittaker, David T.E.
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Read Online
- Asymmetric catalysis. Part 153: Metal-catalysed enantioselective α-ketol rearrangement
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Promoted by catalytic amounts of Ni complexes tertiary α-hydroxyketones 1a, 3a-5a undergo rearrangement, forming chiral isomers 1b, 3b-5b. The best enantioselection was obtained with the model system 1-benzoylcyclopentanol 4a/2-hydroxy-2-phenylcyclohexanone 4b. In a ligand screening 2-[4-(S)-tert-butyloxazolin-2-yl]pyridine gave the highest enantiomeric excess of 46% (S)-4b. The analogous isomerisation reactions of α-hydroxyimines 6a, 7a forming chiral α-aminoketones 6b, 7b were established.
- Brunner, Henri,Kagan, Henri B.,Kreutzer, Georg
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p. 2177 - 2187
(2007/10/03)
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