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Indan derivativesQ 1050 DOI: 10.1002/chin.201107125

Sequential Sonogashira/Carbopalladative Cyclization/Suzuki Reactions Cata-lyzed by a Single Palladium Source by Using Protected Homopropargyl Alcohol. — Protected homopropargyl alcohol (I) is converted into indene derivatives by a new cascade sequence including Sonogashira coupling with aryl iodides (II) or aryl bro-mides (V), carbopalladative cyclization and Suzuki coupling reactions with aryl boron-ic acids (III). Using aryl bromides (V), a catalytic amount of potassium iodide is nec-essary to achieve better results. The reaction proceeds under mild conditions tolerating various para-substituted aryl substrates. In contrast, no reaction is observed for ortho--substituted aryl substrates due to their steric hindrance. Instead of the latter Suzuki re-action, Stille coupling with phenyltributyltin (VI) also results in the formation of (IVa) with identical yield. — (WANG, X.; LIU*, L.; CHANG, W.; LI, J.; Eur. J. Org. Chem. 2010, 28, 5391-5396, http://dx.doi.org/10.1002/ejoc.201000515 ; State Key Lab. Elem.-Org. Chem., Nankai Univ., Tianjin 300071, Peop. Rep. China; Eng.) — S. Adam

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ChemInform 2011, 42, issue 07 © 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim