García-Mingüens, Eduardo, Nájera, Carmen, Sansano, Jose M.
Diastereoselective Synthesis of Nitropyrrolizidines from Enantiopure exo- 4-Nitro-3,5-diphenylproline through 1,3-Dipolar Cycloadditions of non- Stabilized Azomethine Ylides
Letters in Organic Chemistry. 2018, 15(5): 431-440. doi:10.2174/1570178615666171221142214
URI: http://hdl.handle.net/10045/74910
DOI: 10.2174/1570178615666171221142214
ISSN: 1570-1786 (Print)
Abstract: 
Enantiopure exo-4-nitro-3,5-diphenylproline reacts with aldehydes and electrophilic alkenes, in good yields, through a multicomponent 1,3-dipolar cycloaddition where the intermediate azomethine ylide is generated by the decarboxylative route. The reactions with maleimides afford diastereoselectively nitropyrrolizidines. Dimethyl fumarate and 1,2-bis(phenylsulfonyl)ethylene also give variable mixtures of diastereoisomeric nitropyrrolizidines. The replacement of aldehydes by phenyl-3-buten-2- one also affords satisfactory results with high diastereoselection although in lower yields. The stereochemical outcome is studied and defined according to the absolute configuration of the resulting cycloadducts.
Keywords:Pyrrolizidine, Nitroprolinates, Cycloaddition, Azomethine ylides, Decarboxylation, Multicomponent
Bentham Science Publishers
info:eu-repo/semantics/article