Ru-mediated selective addition reactions of carboxylic acids to internal and terminal alkynes
Ru-mediated selective addition reactions of carboxylic acids to internal and terminal alkynes
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DOI：
10.1016/j.jorganchem.2010.05.018
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发表时间：
2010-09-01
影响因子：
2.3
通讯作者：
Imamoglu, Yavuz
中科院分区：
文献类型：
--
作者：
Karabulut, Solmaz;Ozturk, Bengi Ozgun;Imamoglu, Yavuz
本研究使用 Ru=CHPhCl2(PCy3)(IPr)（IPr：[1,3-双（2,6-二异丙基苯基）-1,3-二氢-2H-咪唑-2-亚基]）检查了三氯乙酸与内部炔烃的亲核加成。该反应在温和的实验条件下以良好的收率和高 Z 选择性进行。相同的钌络合物还被证明可以催化羧酸（乙酸、三氯乙酸、反式-2-辛烯酸、4-环辛烯酸）加成到末端炔烃上。这些反应以 80-100% 的产率进行，显示出有利于宝石异构体的高立体选择性。发现加成反应的生产率和选择性取决于所用羧酸的性质。酸度较高时，反应产率增加，但立体选择性下降。烯酸的反应对羧酸加成到末端炔烃的三键而不是三键加成到烯酸的双键表现出高选择性。为了评估末端炔烃的羧酸加成反应获得的结果，还研究了末端炔烃（苯乙炔、1-辛炔、1-庚炔）的同二聚。研究发现，当使用脂肪族炔烃时，末端炔烃的均二聚反应具有较高的宝石选择性，而使用芳香族炔烃时，反应会产生较高的 Z 选择性，表明选择性取决于所用炔烃的性质。 (C) 2010 Elsevier B.V. 保留所有权利。
This study examined the nucleophilic addition of trichloroacetic acid to internal alkynes using Ru=CHPhCl2(PCy3)(IPr) (IPr: [1,3-Bis(2,6-diisopropylphenyl)-1,3-dihydro-2H-imidazo-2-ylidene]). This reaction was performed in good yield with high Z-selectivity under mild experimental conditions. The same ruthenium complex was also shown to catalyse carboxylic acid (acetic acid, trichloroacetic acid, trans-2-octenoic acid, 4-cyclooctenoic acid) addition to terminal alkynes. These reactions proceeded in 80-100% yield, showing a high stereoselectivity favouring the gem isomer. The productivity and selectivity of the addition reaction was found to depend on the nature of the carboxylic acid that was used. With higher acidities, the yield of the reaction increased but the stereoselectivity decreased. The reactions of enoic acids, showed a high selectivity towards carboxylic acid addition to the triple bond of terminal alkynes, rather than triple bond addition to the double bond of the enoic acids. To evaluate the results obtained from the carboxylic acid addition reaction of terminal alkynes, the homodimerisation of terminal alkynes (phenylacetylene, 1-octyne, 1-heptyne) was also studied. The homodimerisation of terminal alkynes is found to proceed with high gem selectivity when employing aliphatic alkynes, whereas the reaction resulted in high Z-selectivity with aromatic alkynes, showing that the selectivity is dependent on the nature of the alkyne used. (C) 2010 Elsevier B. V. All rights reserved.