Yunusova Sevilya N, Novikov Alexander S, Soldatova Natalia S, Vovk Mikhail A, Bolotin Dmitrii S
Institute of Chemistry, Saint Petersburg State University Universitetskaya Nab. 7/9 Saint Petersburg 199034 Russian Federation
Center for Magnetic Resonance, Saint Petersburg State University Universitetskii Pr., 26 Saint Petersburg 198504 Russian Federation.
RSC Adv. 2021 Jan 22;11(8):4574-4583. doi: 10.1039/d0ra09640g. eCollection 2021 Jan 21.
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 -acetyl hydrazides with acetyl acetone to give -acyl pyrazoles. The highest activity was observed for dibenziodolium triflate, for which 10 mol% resulted in the generation of -acyl pyrazole from acyl hydrazide and acetyl acetone typically at 50 °C for 3.5-6 h with up to 99% isolated yields. H NMR titration data and DFT calculations indicate that the catalytic activity of the iodine(iii) is caused by the binding with a ketone.
在酰基肼与乙酰丙酮的克诺尔型反应中，生成酰基吡唑时，高价碘（III）衍生物比其他含脂肪族和芳香族碘（I）或溴（I）的底物表现出更高的催化活性。三氟甲磺酸二苯碘鎓的催化活性最高，10 mol%的该物质通常在50°C下反应3.5 - 6小时，能使酰基肼和乙酰丙酮生成酰基吡唑，分离产率高达99%。核磁共振氢谱滴定数据和密度泛函理论计算表明，碘（III）的催化活性是由其与酮的结合引起的。
