Get access

Enantioselective Cycloadditions of 2-Alkenoylpyridine-N-oxides Catalysed by a Bis(oxazoline)/CuII Complex: Structure of the Reactive Intermediate

Authors

  • Dr. Alessandro Livieri,

    1. Department of Organic Chemistry, University of Pavia, V.le Taramelli, 10, 27100 Pavia (Italy), Fax: (+39) 0-382-987-323
    Search for more papers by this author
  • Dr. Massimo Boiocchi,

    1. Centro Grandi Strumenti, University of Pavia v. Bassi, 8, 27100 Pavia (Italy)
    Search for more papers by this author
  • Prof. Giovanni Desimoni,

    1. Department of Organic Chemistry, University of Pavia, V.le Taramelli, 10, 27100 Pavia (Italy), Fax: (+39) 0-382-987-323
    Search for more papers by this author
  • Prof. Giuseppe Faita

    Corresponding author
    1. Department of Organic Chemistry, University of Pavia, V.le Taramelli, 10, 27100 Pavia (Italy), Fax: (+39) 0-382-987-323
    • Department of Organic Chemistry, University of Pavia, V.le Taramelli, 10, 27100 Pavia (Italy), Fax: (+39) 0-382-987-323
    Search for more papers by this author

Abstract

Diels–Alder and 1,3-dipolar cycloadditions involving (E)-3-aryl-1-(pyridin-2-yl-N-oxide)prop-2-en-1-ones as the 2π components are efficiently catalysed by bis(oxazoline)–CuII complexes. The cycloadducts are obtained in quantitative yields with up to 98 % ee; absolute configurations were determined by X-ray analysis. The structure of the reactive complex, determined by X-ray analysis, is fully consistent with the stereochemical outcome of the catalysed process (approach of the diene or nitrone to the less hindered face of the coordinated pyridine-N-oxide derivative).

Ancillary