Cesium fluoride catalyzed Aza-Michael addition reaction in aqueous media

A highly efficient and sustainable synthesis of dihydropyrano[2,3-c]pyrazoles using polystyrene-supported p-toluenesulfonic acid as reusable catalyst

“…In continuation of our effort toward the development of ecofriendly synthetic protocols, (Gujar, Chaudhari, Kawade, & Shingare, 2014;Labade, Pawar, & Shingare, 2011;Labade, Shinde, & Shingare, 2013;Niralwad, Shingate, & Shingare, 2011;Shinde, Kategaonkar, Shingate, & Shingare, 2011) it was thought worthwhile to a disclose new and expeditious route for the synthesis of dihydropyrano[2,3-c] pyrazoles using polystyrene-supported p-toluenesulfonic acid due to its many practical benefits which attracted our interest.…”

Aza‐Michael Reaction: A Decade Later – Is the Research Over?

“…However, when aniline is subjected to undergoing this reaction, starting materials are recovered even after prolonged reaction time by both conventional and non‐conventional methods [116] . This method offers remarkable advantages such as the simple experimental procedure, mild reaction conditions, lower reaction time (especially, under ultrasonic conditions), and higher product yields, avoiding hazardous organic solvents.…”

Aza‐Michael addition of 1,2‐diazoles to structurally diverse enones: Efficient methods toward β‐amino ketones

“…However, aza‐Michael addition approach is a standout protocol among the most essential and powerful route for C‐N bond formation; nevertheless addition of azoles to cyclic enones is quite troublesome because of less nucleophilic nature of the azoles and due to the structural complexity of the cyclic enones. [ 2 ] It is evident from the literature reports that metals, [ 3 ] lanthanides, [ 4 ] inorganic strong supports, [ 5 ] fluorides, [ 6 ] organocatalysts, [ 7 ] bases, [ 8 ] and even enzymes [ 9 ] were utilized toward the successful accomplishment of aza‐Michael addition reactions. In recent times, catalyst‐free aza‐Michael addition reactions have also been explored using azoles and β,γ‐unsaturated‐α‐keto esters/electron deficient olefins.…”