Ruthenium(II) Complexes with Chiral Tetradentate P2N2 Ligands Catalyze the Asymmetric Epoxidation of Olefins with H2O2
| Autor: | Massimiliano Valentini, Antonio Mezzetti, Robert M. Stoop, Stephan Bachmann |
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| Rok vydání: | 2000 |
| Předmět: | |
| Zdroj: | Organometallics. 19:4117-4126 |
| ISSN: | 1520-6041 0276-7333 |
| DOI: | 10.1021/om000481v |
| Popis: | The five-coordinate complexes of the type [RuCl(PNNP)]PF6 (PNNP = tetradentate ligand with a P2N2 donor set) are prepared by chloride abstraction from [RuCl2(PNNP)]. A mixture of Δ-cis-β- and Λ-cis-β-[RuCl2(1a-κ4P,N,N,P)] (2a; 1a = N,N‘-bis[o-(diphenylphosphino)benzylidene]-2,2‘-diimino-1,1‘-(S)-binaphthylene), prepared by reaction of 1a with [RuCl2(PPh3)3], reacts with Tl[PF6], giving the five-coordinate [RuCl(1a-κ4P,N,N,P)]PF6 (3a). The related trans-[RuCl2(1b-κ4P,N,N,P)] (2b; 1b = N,N‘-bis[o-(diphenylphosphino)benzylidene]-(1S,2S)-diiminocyclohexane) reacts with Tl[PF6] to give [RuCl(1b-κ4P,N,N,P)]PF6 (3b). With the amino ligand N,N‘-bis[o-(diphenylphosphino)benzylidene]-(1S,2S)-diaminocyclohexane (1c), the aqua complex [RuCl(OH2)(1c-κ4P,N,N,P)]PF6 (5c) is obtained by reaction of Tl[PF6] with [RuCl2(PPh3)(1c-κ3P,N,N)] (4), which has been isolated and structurally characterized. The reactivity of the five-coordinate 2b with CO and oxygen donors such as water, Et2O, THF, and methanol is reported. Both 3 ... |
| Databáze: | OpenAIRE |
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