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。