Homoleptic pyrazinoic acid transition metal complex as an efficient catalyst toward elegant three-component synthesis of 3,4-dihydro-2H-1,3-benzoxazines

Insights into microwave‐promoted synthesis of 3‐methyl‐4‐phenyl‐4,9‐dihydro‐1H‐pyrazolo[3,4‐d][1,2,4]triazolo[1,5‐a]pyrimidine derivatives catalyzed using new Pd (II),Cu (II),VO (II), and Ag(I) complexes as a heterogeneous catalyst and computational studies

“…[11][12][13][14][15] Among them, heterolytic or homoleptic coordination molecules modeled by pyrazinoic acid using various selected metals are appropriate new catalysts for a broad scale of heterocyclic organic synthesis compounds. 16 Accordingly, 3-methyl-4-phenyl-4,9-dihydro-1Hpyrazolo [3,4-d] [1,2,4]triazolo [1,5-a]pyrimidine derivatives catalyzed by palladium (II) complexes by microwave irradiation under mild conditions have not been reported. Moreover, microwave synthesis of the investigated heterocyclic compounds in catalytic reactions offers numerous advantages, including accelerated reaction rates, improved yield and purity, milder reaction conditions, and safety.…”

“…Various types of Lewis acids and Lewis base such as; ZnBr 2 , FeCl 2 .6H 2 O, FeCl 3 .6H 2 O, TiCl 4 , MnCl 2 , MnO 2 , MgCl 2 , 4H 2 O, CuCl 2 , AlCl 3 , and CuO were tested in selected reaction conditions. When tested DOBPAPd, DOBPACu, DOBPAVO, and DOB-PAAg (Table 6, entries[15][16][17], DOBPAPd was the most effective catalyst, which afforded desired product 4a by 98% yield (Table6, entry 18). When DOBPAPd complex was used without microwave irradiation at the same condition was got a lower yield.…”