Aerobic Linear Allylic C–H Amination: Overcoming Benzoquinone Inhibition

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• 作者：Christopher C. Pattillo ; Iulia I. Strambeanu ; Pilar Calleja ; Nicolaas A. Vermeulen ; Tomokazu Mizuno ; M. Christina White
• 刊名：Journal of the American Chemical Society
• 出版年：2016
• 出版时间：February 3, 2016
• 年：2016
• 卷：138
• 期：4
• 页码：1265-1272
• 全文大小：720K
• ISSN：1520-5126

文摘

An efficient aerobic linear allylic C–H amination reaction is reported under palladium(II)/bis-sulfoxide/Br?nsted base catalysis. The reaction operates under preparative, operationally simple conditions (1 equiv of olefin, 1 atm Ob>2b> or air) with reduced Pd(II)/bis-sulfoxide catalyst loadings while providing higher turnovers and product yields than systems employing stoichiometric benzoquinone (BQ) as the terminal oxidant. Pd(II)/BQ π-acidic interactions have been invoked in various catalytic processes and are often considered beneficial in promoting reductive functionalizations. When such electrophilic activation for functionalization is not needed, however, BQ at high concentrations may compete with crucial ligand (bis-sulfoxide) binding and inhibit catalysis. Kinetic studies reveal an inverse relationship between the reaction rate and the concentration of BQ, suggesting that BQ is acting as a ligand for Pd(II) which results in an inhibitory effect on catalysis.