Gum arabic-OPO₃H₂ as a new natural-based green catalyst for the one-pot pseudo-four-component synthesis of naphtho[1,2-e][1,3]oxazines

Abstract

Gum arabic-OPO3H2 (GA-OPO3H2) as a unique natural-based green catalyst was synthesized by the reaction of phosphorus pentoxide with gum arabic.

Recent advances in the application of magnetic bio-polymers as catalysts in multicomponent reactions

“…In the next step, SbCl 5 was mixed with the reaction mixture in chloroform to provide Fe 3 O 4 @NCs/Sb( v ) 18 ( Scheme 3 ). 52 …”

“…Fe 3 O 4 @NCs/Sb( v ) was used as a Lewis acid for the activation of carbonyl groups, which was investigated in the synthesis of 4 H -pyrimido[2,1- b ]benzothiazoles 22 via the three-component reaction of aldehydes 19, 2-aminobenzothiazole 20, and ethylacetoacetate 21 under solvent-free conditions at 90 °C ( Scheme 4 ). This catalyst was used five times without loss in its catalytic activity, which was compared with Fe 3 O 4 with 39% yield in 3 h. 52 …”

FNAOSiPPEA[]/Zn(II) as a Bifunctional Lewis Acid/ Bronsted Base Heterogeneous Magnetic Nanocatalyst Based on Nano‐Almond Shell for Synthesis of Naphtho[1,3]oxazine Derivatives**

“…1,3-Oxazine derivatives are valuable synthetic mediators and show important biological activities such as sedative, analgesic, antipyretic, anticoagulant, anticonvulsant, anti-tuberculosis, anti-tumor, anti-malarial, and antimicrobial. [14][15][16][17][18][19][20] Recently, 2-aryl (alkyl)-2,3-dihydro-1H-naphtho[1,2-e][1,3]oxazine derivatives, abbreviated ADNO, have been synthesized through multicomponent condensation between formaldehyde, primary amines, and phenolic compounds in the presence of various catalysts such as Fe 3 O 4 @nanowalnut shell/Cu(II), [21] GA-OPO 3 H 2 , [22] ZrOCl 2 .8H 2 O, [23] Fe 3 O 4 @nano-dextrin/Ti(IV), [24] alum (KAl(SO 4 ) 2 .12 H 2 O), [25] PEG-400, [26] and CCl 3 COOH. [27] Therefore, herein we report the synthesis of a new zincdiamine complex of 2-(1-piperazinyl)ethylamine (2-PEA) supported on nano-Fe 3 O 4 @almondshell abbreviated (FNAOSiPPEA/ Zn(II)) as a bifunctional Lewis acid/ Bronsted base nano-catalyst.…”