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.
Donohoe
Timothy J
TJ
Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield Road, Oxford OX1 3TA, UK. timothy.donohue@chem.ox.ac.uk
Freestone
Graeme C
GC
Headley
Catherine E
CE
Rigby
Caroline L
CL
Cousins
Rick P C
RP
Bhalay
Gurdip
G
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