Catalytic asymmetric synthesis of 4-nitropyrazolidines: an access to optically active 1,2,3-triamines
Lennart Lykke1, Bjørn Dreiø Carlsen, Raoní Scheibler Rambo
1Center for Catalysis, Department of Chemistry, Aarhus University , DK-8000 Aarhus C, Denmark.
Abstract:
The first catalytic enantio- and diastereoselective synthesis of 4-nitropyrazolidines is presented. Asymmetric hydrogen-bonding activation of nitro-olefins facilitated the 1,3-dipolar cycloaddition with hydrazones, affording optically active 4-nitropyrazolidines containing three continuous stereogenic centers as a single diastereomer in up to 99% ee. Furthermore, it is demonstrated that the optically active 4-nitropyrazolidines can be applied as precursors for the synthesis of highly interesting 1,2,3-triamines.
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