Exclusive 5-exo-dig Hydroarylation of o-Alkynyl Biaryls Proceeding via C−H Activation Pathway

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• 作者：Natalia Chernyak ; Vladimir Gevorgyan
• 刊名：Journal of the American Chemical Society
• 出版年：2008
• 出版时间：April 30, 2008
• 年：2008
• 卷：130
• 期：17
• 页码：5636 - 5637
• 全文大小：120K
• 年卷期：v.130,no.17(April 30, 2008)
• ISSN：1520-5126

文摘

The first example of the palladium-catalyzed exclusive 5-exo-dig hydroarylation of o-alkynyl biaryls has been demonstrated. In contrast to the reported earlier carbocyclizations proceeding via the Friedel–Crafts mechanism, this hydroarylation efficiently proceeds with electron-neutral and electron-deficient arenes, producing fluorene frameworks with defined stereochemistry of the double bond. On the basis of the high reactivity of electron-deficient arenes toward cyclization, high values of inter- and intramolecular kinetic isotope effects, and the exclusive cis-selectivity of cyclization, a mechanism involving a C−H activation motif has been proposed for this transformation.