Ruthenium-catalyzed intramolecular cyclization of hetero-functionalized allylbenzenes
| Autor: | Isao Furukawa, Yohei Kataoka, Tetsuo Ohta, Yoshihiko Ito, Akio Miyoshi, Yohei Oe |
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| Rok vydání: | 2007 |
| Předmět: |
chemistry.chemical_classification
Olefin fiber Double bond Stereochemistry Ligand Organic Chemistry Intramolecular cyclization chemistry.chemical_element General Medicine Biochemistry Medicinal chemistry Catalysis Ruthenium Inorganic Chemistry chemistry Yield (chemistry) Intramolecular force Materials Chemistry Physical and Theoretical Chemistry Lactone |
| Zdroj: | Journal of Organometallic Chemistry. 692:671-677 |
| ISSN: | 0022-328X |
| Popis: | Intramolecular addition of heterofunctionalities to C C double bonds without β-hydride elimination was investigated and catalyzed by ruthenium complexes. The combination of RuCl 3 · n H 2 O (10 mol%) and 3 equiv. of AgOTf acted as a catalyst for cyclization of 2-allylphenol ( 1a ) to 2,3-dihydro-2-methylbenzofuran ( 2a ) in good yield in the presence of Cu(OTf) 2 as a co-catalyst and PPh 3 as a ligand. This catalyst system also catalyzed the cyclization of 2-allylbenzoic acid to lactone in 91% yield. Then, a new catalyst system (RuCp ∗ Cl 2 ) 2 (1.0 mol%)/4AgOTf/4PPh 3 , was found to be more active even in the absence of Cu(OTf) 2 . Furthermore, this catalysis was applied to asymmetric reaction of 2-allylphenol ( 1a ). When using TolBINAP as a ligand, over 60% e.e. was achieved. |
| Databáze: | OpenAIRE |
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