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

Abstract

The review summarizes the recent advances for the synthesis of bioactive heterocyclic compounds by ultrasound-assisted transition-metal-free catalysis.

Synthesis and characterization of thiophene-derived palladium(ii) complex immobilized on FSM-16 and its application in the novel synthesis of 7-(aryl)-7,12-dihydro-6H-indeno[1,2,4]triazolo[1,5-a]pyrimidine-6-one derivatives

“…[36][37][38] Heterocycles are among the most famous and remarkable compounds of organic chemistry and are also the basis of many drugs, chemicals, veterinarians, and agriculture. [39][40][41] Many natural drugs such as atropine, codeine, reserpine, papaverine, and morphine are heterocycles. 42 Also, new and efficient methods for synthesizing new heterocycles are still in high demand.…”

Facile Synthesis of Pyrazolopyranopyrimidines by Synergism of Ultrasound Irradiation and Biocompatible Inulin Biopolymer as Catalyst

“…In recent years, the usage of ultrasound irradiation as the unconventional source of energy to stimulate organic synthesis has increased as it performs at lower temperature and shorter reaction time with improved selectivity compared to conventional methods [42] . Ultrasound radiation induces acoustic cavitations, producing an enormous sum of energy to overcome the molecular attractive forces between starting substances and assist molecular intermixing, thus speeding up the reaction and enhance product yields [43] …”

“…[42] Ultrasound radiation induces acoustic cavitations, producing an enormous sum of energy to overcome the molecular attractive forces between starting substances and assist molecular intermixing, thus speeding up the reaction and enhance product yields. [43] The use of novel biocompatible catalysts for sustainable organic synthesis has become a crucial research domain among chemists in the present world. Biopolymers as a catalyst has fascinated researchers because of their biodegradable, environmentally safe and non-toxic nature.…”

Recent Advances in the Cascade Cyclization Reactions of 1,7‐Enynes

“…[7,8] So far, considerable efforts have been devoted to the utilization of 1,7-enyne substrates for assembling highly complex and sophisticated structures of chemically and biomedically importance. [9] The tandem transformations of 1,7-enynes have been well documented, and mainly concerned ring-closing reactions involving 6-exo-dig, 6-exo-trig, and 5-exo-trig of metal-carbon units into the polycyclic frameworks. [10,11] Thus, the purpose of this review is to summarize the advancement of cascade cyclization reactions of 1,7enynes, as well as their applications in contemporary areas such as pharmaceutical chemistry, biological chemistry and materials science (Scheme 1).…”