Recent developments on ultrasound-assisted organic synthesis in aqueous medium

Abstract

In the recent past, a number of methods were reported on the application of ultrasound in organic reactions for the synthesis of diverse organic scaffolds. On the other hand, as far as green chemistry is concerned, water is the safest of all solvents. Thus, a "strong collaboration" between ultrasonic irradiation and aqueous medium holds the key to the development of an environmentally sustainable protocol. The present review summarizes the latest developments in ultrasound-assisted and water-mediated organic synthesis reported to date.

Ultrasound-assisted multicomponent synthesis of 4H-pyrans in water and DNA binding studies

“…In the same context, with the aim of developing new synthetic reactions or accelerate them, overcoming the activation energy, unconventional energy sources have been employed [57][58][59][60][61][62][63][64] . In particular, ultrasounds have been used in many transformations.…”

[Bmim]PF6: An efficient tool for the synthesis of diverse bioactive heterocycles

“…The ionic liquid [bmim]PF 6 was found to be an efficient medium for the palladium-catalyzed cyclocarbonylation reaction of o-iodoanilines (12), various allenes (13) and carbon monoxide (14) to afford the corresponding 3-methylene--2,3-dihydro-1H-quinolin-4-ones (15) 61 The entire medium containing the catalyst as well as the promoter was successfully recovered and reused more than four times without significant loss in activities.…”

“…105 The ionic liquid containing catalyst was recovered and recycled several times. Available on line at www.shd.org.rs/JSCS/ carbon monoxide (14) to afford the corresponding lactones (70 and 72) or lactams (74), respectively, in good yields in the presence of 1,4-bis(diphenylphosphino)butane (dppb) as promoter at 90 °C. The ionic liquid containing the palladium catalyst and ligand was recovered and successfully recycled for several runs.…”

“…[10][11][12] Among the other significant parameters, screening of suitable reaction medium plays the key role during organic transformations. 13,14 Worldwide, scientists are trying to modify the reaction media to increase the efficiency of the reaction and reduce their toxicity level as well. In recent times, a wide range of ionic liquids have been employed as reaction media due to their inherent features that include high thermal stability, ability to dissolve a large number of organic and inorganic compounds, non-volatility, low inflammability, easy reusability etc.…”

Ultrasound and Ionic Liquid: An Ideal Combination for Organic Transformations

“…It is well‐established that reaction media play an important role for organic transformations ,. Screening of suitable reaction medium is one of the crucial criteria among the other significant parameters during chemical synthesis .…”