Aldol condensation of acyclic ketones with benzaldehyde and subsequent cyclodehydration to form indenes over halide cluster catalysts

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• 作者：Satoshi Kamiguchi ; Satoru Nishida ; Ikuko Takahashi ; Hideki Kurokawa ; Hiroshi Miura and Teiji Chihara
• 关键词：Catalysis by halide cluster ; Tantalum chloride cluster ; Aldol condensation of acetone with benzaldehyde ; Acyclic ketone ; Cyclodehydration to indene
• 刊名：Journal of Molecular Catalysis A: Chemical
• 出版年：2006
• 出版时间：1 August 2006
• 年：2006
• 卷：255
• 期：1-2
• 页码：117-122
• 全文大小：255 K

文摘

When a molecular halide cluster [(Ta₆Cl₁₂)Cl₂(H₂O)₄]·4H₂O (1)/SiO₂ was treated in a helium stream above 200 °C, it catalyzed the aldol condensation of acetone with benzaldehyde to yield E-4-phenyl-3-buten-2-one. The bromide cluster of Ta and chloride clusters of Nb, Mo, and W of the same octahedral metal framework also catalyzed the reaction. 3,3-Dimethyl-2-butanone combined with benzaldehyde similarly yielded the corresponding aldol condensation product over 1/SiO₂ at 400 °C. On the other hand, 3-pentanone combined with benzaldehyde provided indenes such as E- and Z-1-ethylidene-2-methylindene and 2-methyl-3-vinylindene of the same carbon skeletal structure, which would be formed by cyclodehydration of the aldol condensation product, E-2-methyl-1-phenyl-1-penten-3-one. One of the advantages of halide cluster catalysts is thermal stability, and high temperatures above 350 °C promoted the cyclodehydration.