Synthesis of Chiral Cationic (Diimino- and diaminodiphosphane)ruthenium Complexes and Their Applications in Catalytic Oxidation (see abstract)

Wai Kwok Wong, Xiao Ping Chen, Tat Wai Chik, Wai Yeung Wong, Jian Ping Guo, Fu Wa Lee

Research output: Journal article publicationJournal articleAcademic researchpeer-review

24 Citations (Scopus)

Abstract

Halide abstraction of trans-[RuCl2{κ4-(1R,2R)-PNNP}] {(1R,2R)-PNNP = (1R,2R)-N,N′ -bis[2-(diphenylphosphanyl)-benzylidene]-1,2-diiminocyclohexane} and trans-[RuCl2{κ4-(1R,2R)-P(NH)(NH)P}] {(1R,2R)-P(NH)(NH)P = (1R,2R)-N,N′ -bis[2-(diphenylphosphanyl)benzylidene]-1,2-diaminocyclohexane} with AgBF4in acetonitrile at ambient temperature gave cis-[RuCl(CH3CN){κ4-(1R,2R)-PNNP}][BF4] (1) and cis-[RuCl(CH3CN){κ4-(1R,2R)-P(NH)(NH)P}][BF4] (2), respectively. When I was refluxed in pyridine (py), the coordinated CH3CN was replaced by pyridine to form cis-[RuCl(py){κ4-(1R,2R)-PNNP}][BF4] (3). However, when 2 was refluxed in pyridine, one of the amino moieties (-CH2-NH-)was oxidized to an imino moiety (-CH=N-) with concomitant displacement of the coordinated CH3CN by pyridine to produce cis-RuCl(py){κ4-(1R,2R)-P(N)(NH)P}][BF4] (4). The structures of 3 and 4 were ascertained by X-ray crystallography. Compounds 1-4 are effective catalysts for the epoxidation of various olefins with air. A turnover frequency of up to 733 h-1and an enantiomeric excess of up to 24% were obtained for the epoxidation of styrene catalysed by 2. Compound 2 can also catalyse the epoxidation, dehydrogenation and C-H activation of various olefins, alcohols and alkanes by tert-butyl hydroperoxide with high chemical selectivity. KGaA, 69451 Weinheim, Germany, 2003.
Original languageEnglish
Pages (from-to)3539-3546
Number of pages8
JournalEuropean Journal of Inorganic Chemistry
Issue number19
DOIs
Publication statusPublished - 6 Oct 2003
Externally publishedYes

Keywords

  • Catalysis
  • Chiral complexes
  • N,P ligands
  • Oxidation
  • Ruthenium

ASJC Scopus subject areas

  • Inorganic Chemistry

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