One-pot synthesis of 1,3,5-tribenzoylbenzenes by three consecutive Michael addition reactions of 1-phenyl-2-propyn-1-ones in pressurized hot water in the absence of added catalysts.
One-pot synthesis of 1,3,5-tribenzoylbenzenes by three consecutive Michael addition reactions of 1-phenyl-2-propyn-1-ones in pressurized hot water in the absence of added catalysts.
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DOI：
10.1002/chem.201001946
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发表时间：
2011-01
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影响因子：
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通讯作者：
Makoto Tanaka;Kazuya Nakamura;Tatsuya Iwado;Toshiyuki Sato;M. Okada;K. Sue;H. Iwamura;T. Hiaki
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文献类型：
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作者：
Makoto Tanaka;Kazuya Nakamura;Tatsuya Iwado;Toshiyuki Sato;M. Okada;K. Sue;H. Iwamura;T. Hiaki
1-苯基-2-丙炔-1-酮在加压热水中环三聚，一锅生成 1,3,5-三苯甲酰苯，在 200 °C 下 7 分钟后收率 65%，在 150 °C 下 60 分钟后收率 74%。该反应在没有水的情况下不会发生，并且添加碱促进了250℃下的反应，这表明了三连续迈克尔加成反应的机制。反应速率随温度升高而增加，但 1,3,5-三苯甲酰苯的产率下降，代价是在较高温度下形成作为副产物的苯乙酮。苯环上的对甲基和对氯取代基分别延迟和增强了反应。提出了一种涉及苯甲酰乙醛的烯醇在通向 1,3,5-三苯甲酰苯和苯乙酮的途径的分支点的机制。
Cyclotrimerization of 1-phenyl-2-propyn-1-one in pressurized hot water gave 1,3,5-tribenzoylbenzene in one pot in 65 % yield after 7 min at 200 °C, or in 74 % yield after 60 min at 150 °C. The reaction did not take place in the absence of water, and added base promoted the reaction at 250 °C, suggesting a mechanism of three-consecutive Michael addition reactions. The reaction rates increased with temperature, but the yield of 1,3,5-tribenzoylbenzene decreased at the expense of formation of acetophenone as a side product at higher temperatures. p-Methyl and p-chloro-substituents on the phenyl ring retarded and enhanced the reaction, respectively. A mechanism involving the enol of benzoylacetaldehyde at a branching point of the pathway leading to 1,3,5-tribenzoylbenzene and acetophenone was suggested.