The Suzuki–Miyaura Cross-Coupling Reaction of Halogenated Aminopyrazoles: Method Development, Scope, and Mechanism of Dehalogenation Side Reaction

详细信息    查看全文

• 作者：Lukáš JedinákRenáta Zátopková ; Hana Zemánková ; Alena Šustková ; Petr Cankař
• 刊名：Journal of Organic Chemistry
• 出版年：2017
• 出版时间：January 6, 2017
• 年：2017
• 卷：82
• 期：1
• 页码：157-169
• 全文大小：666K
• ISSN：1520-6904

文摘

The efficient Suzuki–Miyaura cross-coupling reaction of halogenated aminopyrazoles and their amides or ureas with a range of aryl, heteroaryl, and styryl boronic acids or esters has been developed. The method allowed incorporation of problematic substrates: aminopyrazoles bearing protected or unprotected pyrazole NH, as well as the free amino or N-amide group. Direct comparison of the chloro, bromo, and iodopyrazoles in the Suzuki–Miyaura reaction revealed that Br and Cl derivatives were superior to iodopyrazoles, as a result of reduced propensity to dehalogenation. Moreover, the mechanism and factors affecting the undesired dehalogenation side reaction were revealed.