Highly enantioselective intramolecular 1,3-dipolar cycloaddition: a route to piperidino-pyrrolizidines.
Enantioselective catalytic intermolecular 1,3-dipolar cycloadditions are powerful methods for the synthesis of heterocycles. In contrast, intramolecular enantioselective 1,3-dipolar cycloadditions are virtually unexplored. A highly enantioselective synthesis of natural-product-inspired pyrrolidino-piperidines by means of an intramolecular 1,3-dipolar cycloaddition with azomethine ylides is now reported. The method has a wide scope and yields the desired cycloadducts with four tertiary stereogenic centers with up to 99% ee. Combining the enantioselective catalytic intramolecular 1,3-dipolar cycloaddition with a subsequent diastereoselective intermolecular 1,3-dipolar cycloaddition yielded complex piperidino-pyrrolizidines with very high stereoselectivity in a one-pot tandem reaction.
Max-Planck-Institut für Molekulare Physiologie, Abteilung Chemische Biologie, Otto-Hahn-Strasse 11, 44227 Dortmund (Germany).
Srinivasa Rao
SR
Vidadala
Christopher
C
Golz
Carsten
C
Strohmann
Constantin-G
CG
Daniliuc
Herbert
H
Waldmann
D061565:Cycloaddition Reaction; D009682:Magnetic Resonance Spectroscopy; D010880:Piperidines / Q000737:chemistry*; D011758:Pyrroles / Q000737:chemistry*; D013237:Stereoisomerism
D010880:Piperidines; D011758:Pyrroles
asymmetric catalysis; biology-oriented synthesis; cycloaddition; pyrrolidino-piperidines; pyrrolizidines