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: Enantioselective reductive cyclization of 1,6-enynes via rhodium-catalyzed asymmetric hydrogenation: C-C bond formation precedes hydrogen activation.
    Author: Jang HY, Hughes FW, Gong H, Zhang J, Brodbelt JS, Krische MJ.
    Journal: J Am Chem Soc; 2005 May 04; 127(17):6174-5. PubMed ID: 15853314.
    Abstract:
    Asymmetric hydrogenation of 1,6-enynes using chirally modified cationic rhodium precatalysts enables enantioselective reductive cyclization to afford alkylidene-substituted carbocycles and heterocycles in a completely atom economical fashion. Good to excellent yields and exceptional levels of asymmetric induction are observed across a structurally diverse set of substrates. Mechanistic studies involving hydrogen-deuterium crossover experiments, along with the observance of nonconjugated cycloisomerization products 14c and 15c, suggest rhodium(III) metallocyclopentene formation occurs in advance of hydrogen activation. This oxidative coupling-hydrogenolytic cleavage motif should play a key role in the design of related hydrogen-mediated couplings.
    [Abstract] [Full Text] [Related] [New Search]