Copper-Mediated Fluoroalkylation Reactions with Iododifluoroacetamides: Controlling the Selectivity among Cross-Coupling, Intramolecular Cyclization, and Homocoupling Reactions

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• 作者：Jieming Zhu ; Wei Zhang ; Laijun Zhang ; Jun Liu ; Ji Zheng ; Jinbo Hu
• 刊名：Journal of Organic Chemistry
• 出版年：2010
• 出版时间：August 20, 2010
• 年：2010
• 卷：75
• 期：16
• 页码：5505-5512
• 全文大小：1059K
• 年卷期：v.75,no.16(August 20, 2010)
• ISSN：1520-6904

文摘

Cu-mediated fluoroalkylation reactions with iododifluoroacetamides 1 have been systematically investigated. It was found that three types of reactions may coexist in Cu-mediated reactions between iododifluoroacetamides and aryl/alkenyl iodides: cross-coupling, intramolecular cyclization, and homocoupling reactions. The selectivity among these three types of reactions could be controlled by tuning the substituents on the nitrogen atom of iododifluoroacetamides, and/or by removing the cross-coupling reaction partner (aryl/alkenyl halides). The general rule is as follows: (a) in the presence of proper aryl/alkenyl iodides, the cross-coupling products 2 (or 6) are generally formed as the major products; (b) in the absence of aryl/alkenyl iodides, and when R¹ = alkyl and R² = aryl groups, or when R¹ = R² = aryl groups, the intramolecular cyclization products 3 can be formed predominantly; and (c) in the absence of aryl/alkenyl iodides, and when R¹ = R² = alkyl groups, or when R¹ = H and R² = alkyl, aryl groups, the homocoupling products 4 can be formed dominantly. Our experimental results also indicate that in many cases when cross-coupling, homocoupling, and intramolecular cyclization reactions coexist in the Cu-mediated reaction system, the reactivity decreases in the following order: cross-coupling > intramolecular cyclization > homocoupling.