Microwave Irradiated, Sodium Aluminate Supported and Zinc Catalyzed Suzuki-Miyaura Cross-Coupling Reaction on Fused Tricyclic Oxa-Aza-Quinolone: A Green Protocol

Alternative synthesis methods are need of the hour to provide easy protocol for synthesizing biologically active heterocyclic compounds. In this connection, this paper describes the development of a concise, convergent protocol for diversely substituted Suzuki–Miyaura cross-coupling reactions of heteroaryl bromides and boronic acids under microwave irradiation using Sodium aluminate (NaAlO₂) as a solid support as well as base. According to my knowledge, this is the first report of the strategy that involves the use of zinc as a catalyst on fused tricyclic di-halo quinolones in a solvent-free condition using simple microwave irradiation. Earlier research from the same laboratory established a solid support assisted Suzuki–Miyaura cross-coupling reaction for forming C–C bonds under the influence of microwave irradiation. Therefore, sodium aluminate (NaAlO₂) was attempted as a base and solid support instead of traditional mineral bases. Moreover, zinc was used as a catalyst replacing palladium. The new method is unique and effective due to its energy economy, procedural simplicity, and general applicability. Moreover, the use of Sodium aluminate (NaAlO₂) is expected to extend this green-protocol and atom-friendly chemistry for the synthesis of varied heterocyclic compounds of interest.