Journal article
Ruthenium-Coordinated Spirolactams via Intramolecular Nucleophilic Addition to η6-Arene Metal Complexes
Organometallics, Vol.21(21), pp.4505-4512
10/01/2002
DOI: 10.1021/om020592p
Abstract
Cyclohexadienyl ruthenium(II) complexes incorporating an azaspirocyclic ring system have been prepared from (η6-N-benzyl acetoacetamide)CpRu(II) precursors via an intramolecular nucleophilic aromatic addition/enolate trapping reaction sequence. The spirocyclization process was found to be applicable to a variety of alkyl-, alkoxy-, and chloro-substituted N-benzyl acetoacetamide ligands, and isolated yields of the cyclohexadienyl products ranged from 44% to 86%. In contrast, related arene ruthenium complexes prepared from benzyl acetoacetate and phenethyl acetoacetamide failed to undergo spirocyclization, but were found to participate in intramolecular SNAr reactions (leading to formation of tetralone and benzazepinone ring systems, respectively). Thus, the conformational mobility of the side chain linking the nucleophilic center to the coordinated arene ring appears to be important in governing the regioselectivity of aromatic addition in these reactions. Several spirolactam complexes were reduced with LiAlH4 to the corresponding Ru-coordinated spirocyclic amines; however, attempts to remove the cyclohexadienyl moiety from the CpRu(II) center via ligand protonation were unsuccessful.
Details
- Title: Subtitle
- Ruthenium-Coordinated Spirolactams via Intramolecular Nucleophilic Addition to η6-Arene Metal Complexes
- Creators
- F. Christopher Pigge - Department of Chemistry and Biochemistry, University of Missouri, St. Louis, 8001 Natural Bridge Road, St. Louis, Missouri 63121-4499John J Coniglio - Department of Chemistry and Biochemistry, University of Missouri, St. Louis, 8001 Natural Bridge Road, St. Louis, Missouri 63121-4499Shiyue Fang - Department of Chemistry and Biochemistry, University of Missouri, St. Louis, 8001 Natural Bridge Road, St. Louis, Missouri 63121-4499
- Resource Type
- Journal article
- Publication Details
- Organometallics, Vol.21(21), pp.4505-4512
- DOI
- 10.1021/om020592p
- ISSN
- 0276-7333
- eISSN
- 1520-6041
- Language
- English
- Date published
- 10/01/2002
- Academic Unit
- Chemistry; Radiology
- Record Identifier
- 9984217456702771
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