Chapter 2
Efficient Organic Synthesis: What
Ultrasound Makes Easier
Abstract The application of ultrasound waves to induce and enhance chemical reactivity dates back to the pioneering studies by Richards and Loomis in the late 1920s.
The long journey, now entering the twenty-first century, has been accompanied by
decades of low and high research activity. But arguably, the marriage between synthesis, organic synthesis in particular, and sonochemistry has been especially fruitful
from the 1980s onwards. We now realize the pluses conveyed by sonication, in
terms of efficiency, acceleration and selectivity. Mechanistic switching and/or different product distribution relative to non-irradiated conditions also represent salient
features observed frequently in sonochemical reactions. This chapter summarizes
a series of fundamental ideas in organic sonochemistry and introduces the subject
within the framework of green chemistry and sustainability. Representative examples
gathered in recent literature help to appreciate the added value of sonochemistry as
tool.
2.1 Sonochemistry for Sustainability. General Remarks
The concepts of green chemistry, according to its 12 principles, and green engineering have now become dominant and essential considerations for all chemists across
the whole range of chemical disciplines. If one may say so, green chemistry is often
invoked as magic touch, in the hope such words will promote our own research still
further. Inevitably, this has generated both misuse and abuse (vide infra), although
we should nevertheless be strongly committed to building a green chemistry toolbox
that can deliver sustainability throughout processes, from their first design basis,
and thus reduce anthropogenic impact on human health and the environment.
Sonochemistry focuses primarily on processes and transformations that are aided
by acoustic cavitation. In line with other enabling technologies, such as electrochemistry and photochemistry, sonochemistry (effects caused by the propagation of
pressure waves in liquids) has the potential to dramatically influence a wide variety
of chemical reactions by reducing their reaction times, increasing yields and halting
the formation of unwanted by-products and competing pathways. It is not an exag© The Author(s), under exclusive licence to Springer Nature Switzerland AG 2018
J.-M. Lévêque et al., Organic Sonochemistry, Ultrasound and Sonochemistry,
https://doi.org/10.1007/978-3-319-98554-1_2
17
Efficient Organic Synthesis: What
Ultrasound Makes Easier
Abstract The application of ultrasound waves to induce and enhance chemical reactivity dates back to the pioneering studies by Richards and Loomis in the late 1920s.
The long journey, now entering the twenty-first century, has been accompanied by
decades of low and high research activity. But arguably, the marriage between synthesis, organic synthesis in particular, and sonochemistry has been especially fruitful
from the 1980s onwards. We now realize the pluses conveyed by sonication, in
terms of efficiency, acceleration and selectivity. Mechanistic switching and/or different product distribution relative to non-irradiated conditions also represent salient
features observed frequently in sonochemical reactions. This chapter summarizes
a series of fundamental ideas in organic sonochemistry and introduces the subject
within the framework of green chemistry and sustainability. Representative examples
gathered in recent literature help to appreciate the added value of sonochemistry as
tool.
2.1 Sonochemistry for Sustainability. General Remarks
The concepts of green chemistry, according to its 12 principles, and green engineering have now become dominant and essential considerations for all chemists across
the whole range of chemical disciplines. If one may say so, green chemistry is often
invoked as magic touch, in the hope such words will promote our own research still
further. Inevitably, this has generated both misuse and abuse (vide infra), although
we should nevertheless be strongly committed to building a green chemistry toolbox
that can deliver sustainability throughout processes, from their first design basis,
and thus reduce anthropogenic impact on human health and the environment.
Sonochemistry focuses primarily on processes and transformations that are aided
by acoustic cavitation. In line with other enabling technologies, such as electrochemistry and photochemistry, sonochemistry (effects caused by the propagation of
pressure waves in liquids) has the potential to dramatically influence a wide variety
of chemical reactions by reducing their reaction times, increasing yields and halting
the formation of unwanted by-products and competing pathways. It is not an exag© The Author(s), under exclusive licence to Springer Nature Switzerland AG 2018
J.-M. Lévêque et al., Organic Sonochemistry, Ultrasound and Sonochemistry,
https://doi.org/10.1007/978-3-319-98554-1_2
17