Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes, 748, CEP 05508-000 São Paulo, SP, Brazil.
Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes, 748, CEP 05508-000 São Paulo, SP, Brazil.
Ultrason Sonochem. 2021 Nov;79:105778. doi: 10.1016/j.ultsonch.2021.105778. Epub 2021 Oct 7.
Novel functionalized indolines were synthesized from 2-(((N-aryl)amino)methyl)acrylates and formamides under ultrasonic irradiation for the first time. Aiming to develop a straightforward and easy-to-implement methodology for the synthesis of indolines, an instrumentation setup was designed, including ultrasound (US) equipment (Ultrasonic Horn; tip diameter of 12.7 mm, 20 kHz, maximum power of 400 W), an open reaction flask, and an inexpensive and green catalyst (1 mol%; FeSO·7HO; CAS: 7782-63-0) without the need for anhydrous conditions. The use of the sono-Fenton process in the presence of formamides and 2-(((N-aryl)amino)methyl)acrylates afforded a broad range of functionalized indolines within 60 s in high yields. Several experimental parameters of the ultrasound-assisted reaction were evaluated, such as amplitude (40-80%), sonication time (15-60 s), and pulsed ultrasonic irradiation. A 60 s silent reaction did not produce the desired indoline. The optimized conditions for US-mediated reactions allowed the production of functionalized indolines in high isolated yields (up to 99%, 60 s reaction, pulse ration 1 s:1 s, US amplitude 60 %).
首次在超声辐射下，从 2-(((N-芳基)氨基)甲基)丙烯酰胺和甲酰胺合成了新型功能化吲哚啉。为了开发一种直接且易于实施的吲哚啉合成方法，设计了一种仪器设备，包括超声（US）设备（超声喇叭；尖端直径 12.7mm，20kHz，最大功率 400W）、开放式反应釜和一种廉价且绿色的催化剂（1mol%；FeSO·7HO；CAS：7782-63-0），无需无水条件。在甲酰胺和 2-(((N-芳基)氨基)甲基)丙烯酰胺存在下使用声芬顿工艺，在 60s 内以高收率得到了广泛的功能化吲哚啉。对超声辅助反应的几个实验参数进行了评估，例如幅度（40-80%）、超声时间（15-60s）和脉冲超声辐射。60s 的无声反应没有产生所需的吲哚啉。优化的超声介导反应条件允许以高分离产率（高达 99%，60s 反应，脉冲比 1s:1s，US 幅度 60%）生产功能化吲哚啉。
