Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal.
Dalton Trans. 2019 Feb 7;48(5):1774-1785. doi: 10.1039/c8dt04771e. Epub 2019 Jan 14.
A series of water soluble copper(ii) complexes, [Cu(κOON-HL)(HO)]·2HO (2), [Cu(κO-HL)(HO)] (3), [Cu(κO-HL)(HO)] (5) and [Cu(HO)]·2HL·2(CH)NCHO (7), were prepared by the reaction of Cu(NO)·3HO with sodium (Z)-2-(2-(1-amino-1,3-dioxobutan-2-ylidene)hydrazineyl)benzenesulfonate, [Na(μ-1:2κO,2κO,3κO,4κO-HL)] (1; for 2 and 3), sodium (Z)-3-(2-(1-amino-1,3-dioxobutan-2-ylidene)hydrazineyl)-4-hydroxybenzene-sulfonate, [Na(μ-1κO,2κO-HL)] (4; for 5) or sodium (Z)-2-(2-(1,3-dioxo-1-(phenylamino)butan-2-ylidene)hydrazineyl)naphthalene-1-sulfonate, [Na(μ-1κOO,2κO-HL)(CHOH)] (6; for 7). Compounds 1-7 were fully characterized, also by single-crystal X-ray diffraction analysis, and applied as homogeneous catalysts for the azide-alkyne cycloaddition (AAC) reaction to afford 1,4-disubstituted 1,2,3-triazoles. A structure-catalytic activity relationship has been recognized for the first time on the basis of the occurrence of resonance- and charge-assisted hydrogen bond interactions (RAHB and CAHB), in charge and ligand binding modes, enabling the catalytic activity of the compounds to be ordered as follows: Cu(NO)≪7 (complex salt with RAHB and CAHB) < 3 (with RAHB and CAHB) < 5 (with RAHB) < 2 (neither RAHB nor CAHB). Complex 2, without such non-covalent interactions, was found to be the most efficient catalyst for the AAC reaction, affording up to 98% product yield after being placed for 15 min, at 125 °C, in a water/acetonitrile mixture under low power (10 W) MW irradiation.
一系列水溶性铜（II）配合物，[Cu(κOON-HL)(HO)]·2HO（2），[Cu(κO-HL)(HO)]（3），[Cu(κO-HL)(HO)]（5）和[Cu(HO)]·2HL·2(CH)NCHO（7），是通过 Cu(NO)·3HO 与(Z)-2-(2-(1-氨基-1,3-二氧代丁烷-2-亚基)肼基)苯磺酸钠，[Na(μ-1:2κO,2κO,3κO,4κO-HL)]（1；用于 2 和 3），(Z)-3-(2-(1-氨基-1,3-二氧代丁烷-2-亚基)肼基)-4-羟基苯磺酸钠，[Na(μ-1κO,2κO-HL)]（4；用于 5）或(Z)-2-(2-(1,3-二氧代-1-(苯氨基)丁烷-2-亚基)肼基)萘-1-磺酸钠，[Na(μ-1κOO,2κO-HL)(CHOH)]（6；用于 7）反应制得的。配合物 1-7 均经过充分表征，也通过单晶 X 射线衍射分析进行了表征，并用作叠氮-炔环加成（AAC）反应的均相催化剂，得到 1,4-取代 1,2,3-三唑。首次基于共振和电荷辅助氢键相互作用（RAHB 和 CAHB）的发生，在电荷和配体结合模式下，认识到结构-催化活性关系，使化合物的催化活性有序排列如下：Cu(NO)≪7（具有 RAHB 和 CAHB 的复合物盐）<3（具有 RAHB 和 CAHB）<5（具有 RAHB）<2（既没有 RAHB 也没有 CAHB）。没有这种非共价相互作用的配合物 2 被发现是 AAC 反应最有效的催化剂，在 125°C 下，在水/乙腈混合物中，在低功率（10 W）MW 照射下，放置 15 分钟后，产物收率高达 98%。
