Article

Chiral Brønsted acid-catalyzed asymmetric trisubstituted aziridine synthesis using α-diazoacyl oxazolidinones.

Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502, Japan.
Journal of the American Chemical Society (Impact Factor: 10.68). 06/2011; 133(25):9730-3. DOI: 10.1021/ja203901h
Source: PubMed

ABSTRACT Despite the remarkable advances in catalytic asymmetric aziridinations over the past decades, establishing a general procedure for the stereoselective synthesis of trisubstituted aziridines has remained an elusive goal. Chiral N-triflyl phosphoramide-catalyzed reactions of N-α-diazoacyl oxazolidinones and N-Boc imines were developed as a solution to this unmet challenge.

0 Bookmarks
 · 
95 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Nucleophilic addition to carbon-nitrogen double bonds (imines) represents one of the most common strategies for the synthesis of amine derivatives. In order to circumvent the problem associated with low reactivity of imines in nucleophilic addition, various imines with electron-withdrawing groups at nitrogen have been studied, and many of them were successfully applied in asymmetric methodologies. Especially N-carbamoyl imines were found to be useful in the enantioselective synthesis of various organic compounds, due to their increased reactivity toward nucleophiles as well as limited difficulties connected with the removal of the carbamoyl moiety in target molecules. The aim of this review is to cover enantioselective methods based on N-carbamoyl imines, focusing on synthetically useful protocols.
    Chemical Society Reviews 11/2013; · 24.89 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Sly as Nicox: A palladium-catalyzed addition of arylboronic acids to ketimines has been developed to efficiently provide products in up to 99 % yield and 96 % ee. The reactions could be run under aerobic conditions and with unpurified trifluoroethanol (TFE). A pyrrolidine compound bearing a chiral α-tertiary amine was synthesized in several steps without loss of enantioselectivity. TFA=trifluoroacetate.
    Angewandte Chemie International Edition 06/2013; · 11.34 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Described herein is the use of chiral titanium(iv)-BINOLate to formally implement catalytic asymmetric C(sp(2))-H insertion using N-aryl α-diazoamides. The reaction most likely proceeds via initial asymmetric protonation at the α-carbon of the substrate, followed by the intramolecular electrophilic aromatic substitution.
    Chemical Communications 02/2014; · 6.38 Impact Factor