Accessing <i>N</i>-Acyl Azoles via Oxoammonium Salt-Mediated Oxidative Amidation
作者:John M. Ovian、Christopher B. Kelly、Vincent A. Pistritto、Nicholas E. Leadbeater
DOI:10.1021/acs.orglett.7b00060
日期:2017.3.17
An operationally simple, robust, metal-free approach to the synthesis of N-acyl azoles from both alcohols and aldehydes is described. Oxidative amidation is facilitated by a commercially available organic oxidant (4-acetamido-2,2,6,6-tetramethylpiperidine-1-oxoammonium tetrafluoroborate) and proceeds under very mild conditions for an array of structurally diverse substrates. Tandem reactions of these
Iodonium salts as efficient iodine(<scp>iii</scp>)-based noncovalent organocatalysts for Knorr-type reactions
作者:Sevilya N. Yunusova、Alexander S. Novikov、Natalia S. Soldatova、Mikhail A. Vovk、Dmitrii S. Bolotin
DOI:10.1039/d0ra09640g
日期:——
Hypervalent iodine(III)-derivatives display higher catalytic activity than other aliphatic and aromatic iodine(I)– or bromine(I)-containing substrates for a Knorr-type reaction of N-acetyl hydrazides with acetyl acetone to give N-acyl pyrazoles. The highest activity was observed for dibenziodolium triflate, for which 10 mol% resulted in the generation of N-acyl pyrazole from acyl hydrazide and acetyl
对于N-乙酰酰肼与乙酰丙酮的克诺尔型反应生成N-酰基吡唑,高价碘 ( III ) 衍生物比其他脂肪族和芳香族含碘 () 或溴 () 的底物表现出更高的催化活性。三氟甲磺酸二苯并碘鎓的活性最高,10 mol% 会导致酰肼和乙酰丙酮在 50 °C 下反应 3.5-6 小时,生成N-酰基吡唑,分离收率高达 99%。 1 H NMR滴定数据和DFT计算表明碘( III )的催化活性是由与酮的结合引起的。
Self-Assembly of a U(VI)-Containing Polytungstate Tetramer with Lewis Acid-Base Catalytic Activity for a Dehydration Condensation Reaction
作者:Yu-Feng Liu、Ke Li、Hui-Yong Lian、Xue-Jiao Chen、Xing-Lei Zhang、Guo-Ping Yang
DOI:10.1021/acs.inorgchem.2c02918
日期:2022.12.19
[K2(UO2)4Cl0.5(OH)5.5(γ-SiW10O36)4]28–. Notably, U4 could work as an effective bifunctional Lewisacid-base catalyst for the synthesis of pyrazoles via the condensation of hydrazines with 1,3-diketones under mild conditions, which is attributed to the synergetic effect of the Lewis acidity of U(VI) and the Lewis basicity of γ-SiW10}.
新型含 U(VI) 多钨酸盐 (U-POW) 四聚体 K 1.37 Na 26.63 [K 2 (UO 2 ) 4 Cl 0.5 (OH) 5.5 (γ-SiW 10 O 36 ) 4 ]}·ca66H 2 O ( U 4 ),是使用Keggin型前体[γ-SiW 10 O 36 ] 8–和UO 2 (NO 3 ) 2合成的。4 _通过单晶 X 射线衍射、FT-IR、拉曼光谱、固态漫反射光谱、ICP-OES、ESI-MS、TGA 和 PXRD 进一步表征。中心 K 2 (UO 2 ) 4 Cl 0.5 (OH) 5.5 } 发色团由四个铀酰、四个半数 K 离子、5.5 桥接 μ 2 -OH 和无序 Cl 离子巧妙地构建,并由四个 γ-SiW 10 } 部分构建四聚体 [K 2 (UO 2 ) 4 Cl 0.5 (OH) 5.5 (γ-SiW 10 O 36 ) 4 ]28–。值得注意的是,U
Mitkidou, Sophia; Stephanidou-Stephanatou, Julia; Stephopoulou, Helen, Journal of Heterocyclic Chemistry, 1993, vol. 30, # 2, p. 441 - 444
作者:Mitkidou, Sophia、Stephanidou-Stephanatou, Julia、Stephopoulou, Helen
DOI:——
日期:——
Kashima, Choji; Kita, Isanobu; Takahashi, Katsumi, Journal of Heterocyclic Chemistry, 1995, vol. 32, # 1, p. 25 - 28