One-pot three-component synthesis, structure and redox properties of ferrocenyl isoxazoles

Synthesis of novel ferrocene containing vic-dioxime ligands and their Ni(II), Cu(II) and Co(II) complexes: Spectral, electrochemical and biological activity studies

“…2). The band appearing at about 264 nm is attributed to p/p* transitions [22]. The band around 310 nm can be assigned to the n/p* transitions of the eC¼N group [23].…”

“…The UVevis spectra for the ligands are recorded in DMSO at 200e600 nm. Compounds 1a and 1b showed a strong absorption band at about 260 nm, apparently corresponding to a p/p* transition of aromatic ring or azomethine (eC¼Ne) groups [20], and a shoulder at about 320 nm corresponding to an n/p* transition of the eC¼Ne group [21], and a weak band at about 470 nm that corresponds to a d/d transition for the iron of ferrocene [22]. The 1 H NMR spectra for the ligands showed peaks in the ferrocene region that were characteristic of a monosubstituted ferrocene moiety [23,24].…”

9-Anthraldehyde oxime: a synthetic tool for variable applications

“…A one-pot three-component synthesis was utilized for the preparation of the [3-(9-anthranyl)-5-(trimethylsilyl)isoxazol-4-yl]ferrocenyl methanone (27) allowed to obtain the predicted alkynones, prone to give the addition of the 9-anthracenenitrile oxide. The structure of the obtained isoxazole 27 was confirmed by X-ray structure analyses and the electronic structure was elucidated by computational methods (Scheme 14) [16]. Lucescu and co-workers [9] conducted the cycloaddition reaction between the scarcely described 2-ethynyl-4,6-dimethoxy-1,3,5-triazine (28) as dipolarophile and the 9-anthradehyde oxime in the presence of NCS, potassium bicarbonate in ethyl acetate as solvent (Scheme 15).…”

“…Classical methods involve the reaction between hydroxylamine and α, β-unsaturated carbonyl compounds as well as 1,3-dicarbonyl compounds and α, β-unsaturated nitriles. Moreover, [3 + 2] cycloaddition reactions of alkynes with nitrile oxides are elegant and succinct methods to prepare this class of compounds [16].…”

Acyl Sonogashira Cross-Coupling: State of the Art and Application to the Synthesis of Heterocyclic Compounds

“…Finally, after heating for 30 min under microwaves irradiation, the isoxazole was obtained in moderate to excellent yields (Scheme 34). Moreover, when ferrocenyl moieties were introduced on the acid chloride or on the acetylenic substrate (i.e., R 1 and R 2 , Scheme 45), functionalized substituted redox active isoxazoles were generated [96]. Finally, Müller and Görgen reported the preparation of 3,5-disubstituted isoxazoles [97] through a coupling-azidation-cyclisation sequence (Scheme 46).…”