Enabling technologies for the rapid dechlorination of polychloroarenes and PCBs

•Fast dehalogenations of polychlorinated aromatics and PCBs.•Efficient metal activation and dispersion under ultrasound or high-speed mixing.•Dechlorination reactions under dielectric heating and acoustic cavitation.•Enabling technologies for chemical process intensification and safer protocols.

Dielectric heating and acoustic cavitation (ultrasound or high-performance disperser) may all dramatically enhance conversion rates and yields in heterogeneous metal-assisted organic reactions even when low reagent excesses are used. These so called “enabling technologies” bring with them process intensification, safer protocols, cost reduction and energy savings. We herein describe a series of rapid polychlorinated aromatic and PCBs dechlorinations (15 min) carried out in a moderate excess of metallic sodium and using non-conventional techniques. We compared the results with those obtained for reactions carried out under conventional heating and with those performed with less reactive metals such as magnesium and zinc. In this comparison, high-intensity ultrasound stands out as the technique of choice.

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