Transition-Metal-Mediated Nucleophilic Aromatic Substitution with Acids

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• 作者：Matthew E. O’Reilly ; Samantha I. Johnson ; Robert J. Nielsen ; William A. Goddard III ; T. Brent Gunnoe
• 刊名：Organometallics
• 出版年：2016
• 出版时间：June 27, 2016
• 年：2016
• 卷：35
• 期：12
• 页码：2053-2056
• 全文大小：338K
• 年卷期：0
• ISSN：1520-6041

文摘

Transition-metal-mediated nucleophilic aromatic substitution (S_NAr) reactions prefer that a suitably strong nucleophile be in an aprotic medium. Usually, using protic nucleophile/medium requires high reaction temperatures (>180 °C) to overcome the attenuated nucleophilicity for attack on the arene π system. Surprisingly, we demonstrate herein a Rh^III-mediated S_NAr reaction of a fluoroarene moiety with RCO₂H (R = CH₃, CF₃) in acid media that proceeds at moderate temperatures (<100 °C). We show both by experimental and with DFT calculations that the mechanism proceeds through an internal nucleophilic aromatic substitution (I-S_NAr), where the nucleophile coordinates to the metal ion prior to substitution, thereby mitigating the acid influence.