Synthesis and Antioxidant Activity of Substituted‐1,3,2‐Diazaphosphole 1‐Oxides

Abstract

Synthesis of 1-substituted-1,3,2-diazaphosphole 1-oxides (3a-l) were accomplished via a two-step process. It involves the preparation of diazaphospholo 1-oxide monochloride intermediate (2) and its subsequent reaction with phenols/amino acid esters in dry THF in the presence of triethylamine at 40-45°C. The structures of newly synthesized compounds were characterized by spectral and elemental analysis. The title compounds were evaluated for their in-vitro antioxidant properties.

Green Synthesis, Antioxidant, and Plant Growth Regulatory Activities of Novel α-Furfuryl-2-alkylaminophosphonates

“…Synthesis of diethyl ((((furan-2-ylmethyl)amino) (4-hydroxy-3-methoxyphenyl)methyl) phosphonate) (5a) has been accomplished by two different reaction pathways A and B. Path A involves a straight one-pot and threecomponent, SiO 2 −I 2 -catalyzed Kabachnik−Fields reaction of vanillin (2a), furfurylamine (1), and diethylphosphite (3a) promoted by microwave irradiation. In path B, the reaction is carried out through the addition of diethylphosphite (3a) to the vanillin-derived Schiff base, vanillinidene-furfurylamine (4) (Scheme 1); by following the same procedure, the remaining analogues of the series (5b−j) have been synthesized.…”

“…Because its formation is a reversible process, it is trapped immediately by the catalyst as a four-membered imine− phosphite−SiO 2 −I 2 complex transition state (4ts). Formation of 4ts not only prevents hydrolysis of the imine substrate (4) to the amine (1) and aldehyde (2) by water formed during the condensation of amine (1) and aldehyde that also force the reaction forward. The SiO 2 −I 2 catalyst coordinates to the nitrogen atom of 4ts renders it more electron rich by attracting the electron density of imino bond and facilitates concerted break-up of 4ts in such a way as to lead to the nucleophilic addition of phosphino phosphorus to the iminocarbon atom and electrophilic addition of hydrogen to the iminonitrogen atom to form α-aminophosphonate (5) with simultaneous release of the catalyst.…”

“…Thin-layer chromatography (TLC) analysis has been performed on silica gel-G-coated aluminum sheets as procured from Merck; the analyte mobilities were visualized under UV light, iodine absorption, and ninhydrin solution. 1 H and 13 C NMR and spectral studies were performed on a Bruker 400 MHz spectrometer, and the spectra were recorded in deuterated chloroform (CDCl 3 ) by using tetramethylsilane (TMS) as an internal reference standard.…”

Synthesis and Antioxidant Properties of New Substituted 8‐Methyl‐6‐phenyl‐5,6‐dihydro‐4H‐1,3,2‐benzodioxaphosphocine‐2‐oxide Derivatives

“…The substituted 1,3,7,10‐dioxadiazaphosphacyclotridecinones ( I ) and 1,3,2‐diazaphosphole‐1‐oxides ( II ) are structurally important macrophosphorus heterocyclic molecules, which are active antioxidants shown in Figure .…”

Nucleoside substituted perhydro-1λ5-[1,3,2]diazaphospholo[1,5-a]pyridine-1-thione analogues: Synthesis and evaluation of antiviral and antimicrobial activities

“…[1][2][3] In particular, phosphorus heterocyclic compounds with five and six membered consisting of heteroatoms like nitrogen and oxygen have been attained significant interest due to their important applications in organic synthesis 3 and large varieties of biological activities such as herbicidal, 4,5 insecticidal 6 and antimicrobial. 7 Further, the phosphorous compounds with P-N functionality like diazaphospholes have been attained great interest due to their significant medicinal, pesticidal, [8][9][10][11] antiviral, bactericidal, antioxidant, 12 and anti-carcinogenic activities. It is well recognized that the presence of phosphoryl or thiophosphoryl group in a molecule can control molecular replication, cell biochemistry and metabolic processes in all living species 13 and acts as phosphorylating agent of enzymes possessing good biological activity.…”