Palladium-Catalyzed Coupling of Allenylphosphine Oxides with N-Tosylhydrazones toward Phosphinyl [3]Dendralenes

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• 作者：Mao Mao ; Ling Zhang ; Yao-Zhong Chen ; Jie Zhu ; Lei Wu
• 刊名：ACS Catalysis
• 出版年：2017
• 出版时间：January 6, 2017
• 年：2017
• 卷：7
• 期：1
• 页码：181-185
• 全文大小：495K
• ISSN：2155-5435

文摘

A palladium-catalyzed coupling of allenylphosphine oxides with N-tosylhydrazones, leading to phosphinyl [3]dendralenes, is established. The coupling reaction can be catalyzed by bis(triphenylphosphine)palladium chloride with sodium pivalate as a key additive, presumably via π-allyl-Pd-carbene intermediates. This protocol provides an expedient synthesis of unprecedented multisubstituted phosphinyl [3]dendralenes with a broad substrate diversity and dominant Z-stereoselectivity, depending on the substitution positions. X-ray crystallographic analyses confirm the relative stereochemistry of products and reveal multiple double bonds in a phosphinyl [3]dendralenes array with a “fanlike” dimensional orientation. Further applications of phosphinyl [3]dendralenes to intramolecular cyclization and selective oxidation demonstrate the differentiated reactivities of double bonds.