141197-03-7Relevant articles and documents
Synthesis of substituted pyrrolidines and piperidines from endocyclic enamine derivatives. Synthesis of (±)-laburnamine
Norton Matos, Marta,Afonso, Carlos A.M.,Batey, Robert A.
, p. 1221 - 1244 (2007/10/03)
Functionalization of the α- and β-positions of readily available endocyclic enamine derivatives provides a convenient method for the formation of substituted pyrrolidines and piperidines. α-Alkoxy-β- iodopyrrolidines are formed by the electrophilic addition of iodine to the endocyclic enamine double bond of an N-substituted 2-pyrroline, and nucleophillic attack by an alcohol on the intermediate iodonium ion. The resultant α-alkoxy-β-iodopyrrolidines can be used in radical cyclization reactions to give bicyclic hemiaminal compounds, which can be further elaborated using N-acyliminium chemistry to form α,β-cis- dialkylsubstituted pyrrolidines. A strategy for the incorporation of amino functionality at the β-position was also established by using iodoamination of the enamine double bond, followed by migration of the amine functionality through an aziridination/methanolysis protocol. An alternative method uses an azidomethoxylation protocol using ceric ammonium nitrate (CAN) in the presence of NaN3 and methanol. Formation and trapping of the N-acyliminium ions derived from these substrates, afforded the 3-carbamate and 3-azido-2-substituted products with good diastereoselectivity, with the preferential formation of the trans and cis stereoisomers, respectively. Using the sequential iodoamination, aziridination in methanol and N-acyliminium transformation, trans-3-NHCO2Me-2-allyl-pyrrolidine was prepared, which was used as the key precursor in a synthesis of the natural 1-amidopyrrolizidine alkaloid, (±)-laburnamine.
SC-53116: The First Selective Agonist at the Newly Identified Serotonin 5-HT4 Receptor Subtype
Flynn, Daniel L.,Zabrowski, Daniel L.,Becker, Daniel P.,Nosal, Roger,Villamil, Clara I.,et al.
, p. 1486 - 1489 (2007/10/02)
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