These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Densely Substituted L-Proline Esters as Catalysts for Asymmetric Michael Additions of Ketones to Nitroalkenes.
    Author: Ruiz-Olalla A, Retamosa Mde G, Cossío FP.
    Journal: J Org Chem; 2015 Jun 05; 80(11):5588-99. PubMed ID: 25974363.
    Abstract:
    Homochiral methyl 4-aminopyrrolidine-2-carboxylates are readily obtained by means of asymmetric (3 + 2) cycloadditions between azomethine ylides and nitroalkenes, followed by catalytic hydrogenation of the intermediate 4-nitro cycloadducts. These 4-aminopyrrolidine-2-carboxylate esters belong to the L-series of natural amino acids and catalyze asymmetric Michael additions of ketones to nitroalkenes. However, the enantioselectivity observed with these novel unnatural organocatalysts is opposite to that obtained with L-proline. Since both 4-nitro and 4-amino L-proline esters are efficient organocatalysts of aldol reactions, these results permit to modulate asymmetric quimioselective aldol and conjugate addition reactions.
    [Abstract] [Full Text] [Related] [New Search]