Ultrasound irradiation in heterocycle synthesis: An overview

Abstract

The synthesis of heterocyclic compounds has been a hot topic for several decades. Synthetic organic chemists are always in search of new methodologies which are greener for the synthesis of heterocyclic compounds. The ultrasound‐assisted reactions have contributed much to this field. This review focuses on the impact of sonochemistry in the synthesis of heterocyclic compounds and covers the literature from 2009 to 2020.

Synthesis of Fluorinated 2-Benzylphthalazin-1(2H)-one, 1-Phthalazinamine, and 1-Alkoxy/Benzyloxyphthalazine Derivatives by an Ultrasonication Method

“…It was observed that the ultrasonic method proved to be extremely fast in providing a good overall yield of the product as shown in Table 1. The ultrasonic conditions provided the best results in terms of yield and reaction time, 10,25 when compared with the conventional conditions. It is noteworthy to mention here that no reaction occurred in the absence of a base (entry 9, Table 1).…”

“…The ultrasonic conditions provided better results in terms of the yield and reaction time. 10 25 Note that no reaction occurred in the absence of a base (Table 1 , entry 8).…”

Recientes investigaciones en la síntesis sustentable de pirazolinas

“…Las ventajas con este procedimiento son similares a las obtenidas en reacciones inducidas por radiación de microondas. En la preparación de algunos análogos pirazolínicos, los resultados muestran que existe mejora sustancial en el rendimiento y la tasa de condensación a través de especies altamente reactivas que ayudan en el proceso de reordenamiento y ciclación como consecuencia de la cavitación (Dofe et al, 2020;Saranya et al, 2021).…”

Ultrasound-assisted transition-metal-free catalysis: a sustainable route towards the synthesis of bioactive heterocycles

“…Several review articles demonstrated the application of ultrasound irradiation in diverse synthetic organic transformations. 41–52 Banerjee summarized the ultrasound-assisted organic reactions under catalyst-free conditions in 2017. 53 To our delight, no review articles existed for the transition-metal-free synthesis of diverse heterocyclic compounds based on the sonochemical activation approach.…”