A Highly Practical and General Route for α-Arylations of Ketones Using Bis-phosphinoferrocene-Based Palladium Catalysts
| Autor: | Gabriela Alexandra Grasa, Thomas J. Colacot |
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| Rok vydání: | 2008 |
| Předmět: | |
| Zdroj: | Organic Process Research & Development. 12:522-529 |
| ISSN: | 1520-586X 1083-6160 |
| DOI: | 10.1021/op7002503 |
| Popis: | Well-defined, air-stable Pd complexes of bis-phosphinoferrocene family of catalysts have been studied in the arylation of various ketones with aryl chlorides and aryl bromides. Bis(di-tert-butyl)phosphinoferrocene (DtBPF)-based catalysts such as (DtBPF)PdCl2 and (DtBPF)PdBr2 have been identified as two of the most active catalysts for the α-arylation of a model reaction involving propiophenone and 4-chlorotoluene. The scope of the (DtBPF)PdCl2 catalyst has been efficiently expanded to the arylation of various ketones with aryl chlorides and bromides with up to 97% isolated yields, under relatively mild reaction conditions at low catalyst loadings. The efficacy of the (DtBPF)PdCl2 catalyst was demonstrated at very low catalyst loadings with S/C 10,000 for the difficult aryl bromide, 4-bromoanisole, and 2000 for the electron-neutral aryl chloride, 4-chlorotoluene, on ∼10-g scale with excellent isolated yields and lower Pd in the product (6 and 48 ppm, respectively). Comparative studies on the Pd:DtBPF molar... |
| Databáze: | OpenAIRE |
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