Enantioselective partial reduction of 2,5-disubstituted pyrroles via a chiral protonation approach.
[reaction: see text] The partial reduction of 2,5-pyrrole diester 1 followed by enantioselective protonation in situ to furnish synthetically useful building blocks is described. An enantiomeric excess of up to 74% was achieved using (-)-ephedrine and related analogues as chiral proton sources. The pyrroline product obtained could be recrystallized to give enantiomerically pure material.
Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield Road, Oxford OX1 3TA, UK. timothy.donohue@chem.ox.ac.uk
Timothy J
TJ
Donohoe
Graeme C
GC
Freestone
Catherine E
CE
Headley
Caroline L
CL
Rigby
Rick P C
RP
Cousins
Gurdip
G
Bhalay
D002384:Catalysis; D020650:Combinatorial Chemistry Techniques; D004809:Ephedrine / Q000737:chemistry*; D007202:Indicators and Reagents; D015394:Molecular Structure; D010084:Oxidation-Reduction; D011758:Pyrroles / Q000032:analysis / Q000138:chemical synthesis / Q000737:chemistry*; D013237:Stereoisomerism
D007202:Indicators and Reagents; D011758:Pyrroles; D004809:Ephedrine