Synthesis of Quinoline-Based NNN-Pincer Nickel(II) Complexes: A Robust and Improved Catalyst System for C–H Bond Alkylation of Azoles with Alkyl Halides
| Autor: | Rajesh G. Gonnade, Benudhar Punji, Ulhas N. Patel, Dilip K. Pandey |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
chemistry.chemical_classification
010405 organic chemistry Ligand Organic Chemistry Quinoline chemistry.chemical_element Halide Alkylation 010402 general chemistry 01 natural sciences Medicinal chemistry 0104 chemical sciences Pincer movement Catalysis Inorganic Chemistry chemistry.chemical_compound Nickel chemistry Organic chemistry Physical and Theoretical Chemistry Alkyl |
| Zdroj: | Organometallics. 35:1785-1793 |
| ISSN: | 1520-6041 0276-7333 |
| DOI: | 10.1021/acs.organomet.6b00201 |
| Popis: | The quinoline-based pincer nickel(II) complexes κN,κN,κN-{R2N-C6H4-(μ-N)-C9H6N}NiX ((R2NNNQ)NiCl: R = Me, 2a; R = Et, 2b) were synthesized by the reaction of the ligand precursors (R2NNNQ)H (R = Me, 1a; R = Et, 1b) with (DME)NiCl2 in the presence of Et3N. Similarly, the pincer nickel(II) derivatives (R2NNNQ)NiX (R = Me, X = Br, 3a; R = Et, X = Br, 3b; R = Me, X = OAc, 4a) were obtained by treatment of the ligands (R2NNNQ)H with the nickel precursor (THF)2NiBr2 or Ni(OAc)2. All of these complexes were characterized by 1H and 13C NMR spectroscopy as well as by elemental analysis. Further, the molecular structures of 2a and 3a,b were elucidated by X-ray crystallography. Complex 2a is found to be an efficient catalyst for the direct C–H bond alkylation of substituted benzothiazoles and oxazoles with various unactivated alkyl halides containing β-hydrogens under mild reaction conditions. The catalyst 2a is very robust and was recycled and reused five times for the alkylation reaction without a decrease in its ... |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|