Syntheses of C1-symmetric bidentate ligands having pyridyl and 1,3-Thiazolyl, 1-methylimidazolyl or pyrazinyl donor groups for enantioselective palladium-catalyzed allylic substitution and copper-catalyzed cyclopropanation

Pang Fei Teng, Chui Shan Tsang, Ho Lun Yeung, Wing Leung Wong, Wing Tak Wong, Hoi Lun Kwong

Research output: Journal article publicationJournal articleAcademic researchpeer-review

21 Citations (Scopus)

Abstract

New chiral C1-symmetric bidentate ligands, which possess two different nitrogen heterocycles, 1,3-thiazolyl, 1-methylimidazolyl or pyrazinyl and one pyridyl group, were prepared by Kröhnke condensation in 36-59% overall yield. Stable Pd(II)-allyl and Cu(II) chloride complexes formed by some of the ligands were obtained in 60-65% yields. X-ray crystal structure analysis of a copper(II) complex having 1-methylimidazolyl group indicated that it is a μ-chloro bridge dimer. The Pd(II)-allyl complexes were found to be active catalysts in the asymmetric allylic substitution of 1,3-diphenylprop-2-enyl acetate. The best result observed was 85% e.e. and 99% isolated yield. In addition, the in situ generated Cu(OTf)2 complexes were found to be active catalysts in cyclopropanation of styrene with ethyl diazoacetate.
Original languageEnglish
Pages (from-to)5676-5684
Number of pages9
JournalJournal of Organometallic Chemistry
Volume691
Issue number26
DOIs
Publication statusPublished - 15 Dec 2006
Externally publishedYes

Keywords

  • Allylic Substitution
  • Copper
  • Cyclopropanation
  • Palladium
  • Pyridyl

ASJC Scopus subject areas

  • Biochemistry
  • Physical and Theoretical Chemistry
  • Organic Chemistry
  • Inorganic Chemistry
  • Materials Chemistry

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