Straightforward synthesis of nitroolefins by microwave- or ultrasound-assisted Henry reaction
作者:Jose M. Rodríguez、M. Dolors Pujol
DOI:10.1016/j.tetlet.2011.03.037
日期:2011.5
beta-Nitroalcohol or nitroethylene derivatives can be obtained from aryl aldehydes and nitromethane under Henry condensation conditions. We present a new modification using microwave irradiation or ultrasound as the energy source. Microwave irradiation allowed a novel one-pot synthesis of nitroolefins from aryl aldehydes using ammonium acetate as a catalyst without solvent. Different reaction conditions, such as base, solvent, and reaction time were studied. Only small amounts of beta-hydroxyl nitro compounds were isolated, using microwave irradiation for less than 25 min. In contrast, the use of ultrasound increased the yield of the nitroalcohols. (C) 2011 Elsevier Ltd. All rights reserved.