Ligand-Enabled meta-Selective C–H Arylation of Nosyl-Protected Phenethylamines, Benzylamines, and 2-Aryl Anilines

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• 作者：Qiuping Ding ; Shengqing Ye ; Guolin Cheng ; Peng Wang ; Marcus E. Farmer ; Jin-Quan Yu
• 刊名：Journal of the American Chemical Society
• 出版年：2017
• 出版时间：January 11, 2017
• 年：2017
• 卷：139
• 期：1
• 页码：417-425
• 全文大小：787K
• ISSN：1520-5126

文摘

A Pd-catalyzed, meta-selective C–H arylation of nosyl-protected phenethylamines and benzylamines is disclosed using a combination of norbornene and pyridine-based ligands. Subjecting nosyl protected 2-aryl anilines to this protocol led to meta-C–H arylation at the remote aryl ring. A diverse range of aryl iodides are tolerated in this reaction, along with select heteroaryl iodides. Select aryl bromides bearing ortho-coordinating groups can also be utilized as effective coupling partners in this reaction. The use of pyridine ligands has allowed the palladium loading to be reduced to 2.5 mol %. Furthermore, a catalytic amount of 2-norbornene (20 mol %) to mediate this meta-C–H activation process is demonstrated for the first time. Utilization of a common protecting group as the directing group for meta-C–H activation of amines is an important feature of this reaction in terms of practical applications.