The Effect of β‐Hydrogen Atoms on Iron Speciation in Cross‐Couplings with Simple Iron Salts and Alkyl Grignard Reagents |
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Authors: | Jeffrey D Sears Salvador B Muoz Stephanie L Daifuku Ari A Shaps Stephanie H Carpenter William W Brennessel Michael L Neidig |
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Institution: | Jeffrey D. Sears,Salvador B. Muñoz,Stephanie L. Daifuku,Ari A. Shaps,Stephanie H. Carpenter,William W. Brennessel,Michael L. Neidig |
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Abstract: | The effects of β‐hydrogen‐containing alkyl Grignard reagents in simple ferric salt cross‐couplings have been elucidated. The reaction of FeCl3 with EtMgBr in THF leads to the formation of the cluster species Fe8Et12]2?, a rare example of a structurally characterized metal complex with bridging ethyl ligands. Analogous reactions in the presence of NMP, a key additive for effective cross‐coupling with simple ferric salts and β‐hydrogen‐containing alkyl nucleophiles, result in the formation of FeEt3]?. Reactivity studies demonstrate the effectiveness of FeEt3]? in rapidly and selectively forming the cross‐coupled product upon reaction with electrophiles. The identification of iron‐ate species with EtMgBr analogous to those previously observed with MeMgBr is a critical insight, indicating that analogous iron species can be operative in catalysis for these two classes of alkyl nucleophiles. |
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Keywords: | Eisen Grignard-Reagentien Homogene Katalyse Kreuzkupplungen Rö ntgenbeugung |
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