Merging Metallic Catalysts and Sonication: A Periodic Table Overview

Abstract

Abstract:This account summarizes and discusses recent examples in which the combination of ultrasonic waves and metal-based reagents, including metal nanoparticles, has proven to be a useful choice in synthetic planning. Not only does sonication often enhance the activity of the metal catalyst/reagent, but it also greatly enhances the synthetic transformation that can be conducted under milder conditions relative to conventional protocols. For the sake of clarity, we have adopted a structure according to the periodic-table elements or families, distinguishing between bulk metal reagents and nanoparticles, as well as the supported variations, thus illustrating the characteristics of the method under consideration in target synthesis. The coverage focuses essentially on the last decade, although the discussion also strikes a comparative balance between the more recent advancements and past literature.

General and Prospective Views on Oxidation Reactions in Heterogeneous Catalysis

“…Next, the selective conversion of a variety of substituted cyclic alcohols and alkenes to the corresponding aldehydes, ketones and epoxides under these optimized ultrasonic conditions led to excellent yields (93-99%) within 15-20 min due to synergistic effects between the hybrid nanocatalyst and ultrasonic irradiation (i.e., increased number of molecular interactions leading to higher activities/yields, lowering of the activation energy of the rate limiting step and shorter reaction times). More examples about the coupling of ultrasonic waves and metal-based catalysts in targeted organic compounds synthesis, including oxidation reactions, can be found in the recent review by Domini et al [49]. Although the application of ultrasonic irradiation in the field of selective oxidation reactions offers many advantages, the design of specific sonochemical reactors is however a key issue for large scale developments.…”

“…Additionally, the CuO nanoleaves, prepared by the reported technique, have been observed to be more active, selective and robust (against leaching) than the corresponding nanoleaves prepared without ultrasound irradiation. Readers are also referred to the review by Domini et al [49] for other examples of sonochemically-generated catalysts for various oxidation reactions.…”

General and Prospective Views on Oxidation Reactions in Heterogeneous Catalysis

“…Excellent yields were obtained within 15-30 min due to synergistic effects between the hybrid nanocatalyst and ultrasonic irradiation. More information about the coupling of ultrasonic waves and metal-based catalysts in targeted organic compounds synthesis, including oxidation reactions, can be found in the review of Domini et al [49].…”

“…Additionally, the CuO nanoleaves, prepared by the reported technique, have been observed to be more active, selective and robust (against leaching) than the corresponding nanoleaves prepared without ultrasound irradiation. Readers are also referred to the review of Domini et al [49] for other examples of sonochemically-generated catalysts for various oxidation reactions.…”

The use of ultrasound in the South Cone region. Advances in organic and inorganic synthesis and in analytical methods

“…In this sense, in 2017, reports have been published on the subject of ultrasound and organic chemistry in collaboration between research groups from Argentina, Spain and Italy. These reviews have summarized and discussed recent examples in which the combination of ultrasound energy and metal-based reagents, including metal nanoparticles, have proven to be a useful choice in synthetic planning [7] . It is important to mention that, sonication enhances not only the activity of the metal catalyst/reagent, but also the synthetic transformation that can be conducted under milder conditions relative to conventional protocols.…”