排序方式: 共有6条查询结果,搜索用时 78 毫秒
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Bo-Xiao Tang Ren-Yun Kuang Ji-Wu Wen Xiang Huang Zhen-Xing Zhang Yu-Jun Shen Jia-Ping Chen Wen-Ying Wu 《Tetrahedron letters》2019,60(30):1975-1977
A new and recyclable protocol was developed for Pd(OAc)2-catalyzed the cross-coupling reaction of terminal alkynes with arylboronic acids using environmentally friendly H2O/TBAB as reaction medium. A series of cross-coupling products containing internal acetylenic bond can be obtained with good selectivity and yield. The Pd(OAc)2/H2O/TBAB system was stable in the Sonogashira-type cross-coupling reaction and could be used at least three cycles without considerable decrease in catalytic performance. The results suggest that the unsupported and recyclable systems can be extended to the other realm of CC bond formation in synthetic organic chemistry. 相似文献
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Adriano Carpita 《Tetrahedron letters》2009,50(2):204-144
A straightforward methodology is described for the copper- and solvent-free alkynylations of aryl iodides and bromides using 0.1-0.01 mol % of Pd as Pd EnCat™ 40 or TPP30. High yielding reactions can be achieved under aerobic conditions for a variety of activated and deactivated aryl iodides; a few examples with aryl bromides are also described. Microwave irradiation is able to enhance yields and rates of these reactions. 相似文献
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Kojima N Maezaki N Tominaga H Asai M Yanai M Tanaka T 《Chemistry (Weinheim an der Bergstrasse, Germany)》2003,9(20):4980-4990
All eight diastereoisomers of the monotetrahydrofuran-ring cores of annonaceous acetogenins have been synthesized through utilization of asymmetric alkynylation and stereodivergent one-pot tetrahydrofuran-ring formation. In all cases, the asymmetric alkynylation proceeded with very high diastereoselectivity to give eight kinds of optically pure tetrahydrofuran core from a common alpha-oxyaldehyde. We also describe a comparison of the (1)H NMR, (13)C NMR, and CD spectral data of the eight isomers and give full details of the tetrahydrofuran-ring construction including a model study of asymmetric alkynylation. 相似文献
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Horung-Jyh Chen 《Tetrahedron》2010,66(39):7755-5152
A new, efficient, and inexpensive CuCl2/salicylic acid catalytic system has been developed to catalyze Sonogashira-type cross-coupling of haloarenes and iodoheteroarenes with terminal alkynes under mild reaction conditions to afford the corresponding coupling products in 18-95% yields. The role of salicylic acid might act as a bidentate O,O-donor ligand to activate the catalytic reactivity of copper chloride in coupling reactions was also briefly discussed. 相似文献
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