Iron(III) amino triphenolate complexes with different substituents in the ortho-position of the phenolate moiety (R = H, Me, tBu, or Ph) have been synthesized by the reaction of iron(III) chloride and the sodium salt (Na(3)L(R)) of the requisite ligand. The complexes have been shown to be of either monomeric ([FeL(R)(THF)]) or dimeric ([FeL(R)](2)) nature by a combination of X-ray diffraction, (1)H NMR, solution magnetic susceptibility, and cyclic voltammetry studies. These analytical studies have shown that the monomeric and dimeric [FeL(R)] complexes behave distinctively, and that the dimer stability is a function of the ortho-positioned groups. Both the dimeric as well as monomeric complexes were tested as catalysts for the catalytic cycloaddition of carbon dioxide to oxiranes, and the data show that the monomeric complexes are able to mediate this conversion with significantly higher activities than the dimeric complexes. This difference in reactivity is controlled by the substitution pattern on the ligand L(R), and is in line with the catalytic requisite of binding of the epoxide substrate by the iron(III) center.

The aerobic oxidative CÀC bond cleavage of vicinal diols catalyzed by vanadium amino triphenolates is described. Our results show that CÀC bond cleavage can be performed in different solvents, under an air or oxygen atmosphere, with a large variety of glycols (cyclic or linear, with aromatic or aliphatic substituents) affording the corresponding carbonyl derivatives with high chemoselectivity.Reactions can be performed with as little as 10 ppm of catalyst reaching TON up to 81,000 and TOFs of up to 4150 h À1 . A reaction mechanism, rationalized by density functional theory calculations, is also proposed.

An efficient synthesis of ortho‐substituted trithiophenol amines from commercially available salicaldehydes by Miyazaki–Newman–Kwart rearrangement/threefold reductive amination is reported. The rearrangement has been carried out on salicaldehyde‐O‐thiocarbamates using microwave induced heating, which furnishes a series of thiosalicaldehyde‐S‐carbamates in high yield. The thiocarbamate has three roles: it enables effective S–O rearrangement, acts as a protecting group during the threefold reductive amination and can be easily removed under reductive conditions. The three‐step synthesis has an overall yield ranging from 30–35 %, and it enables access to a series of increasingly important C3v symmetric ligands in a structurally systematic way.

Mononuclear amino triphenolate iron(III) complexes have been synthesized and characterized (UV/Vis spectroscopy, cyclic voltammetry, ESI-MS, 1H NMR spectroscopy, X-ray diffraction). These complexes act as biomimetic catalysts promoting the aerobic auto-oxidation of 3,5-di-tert-butylcatechol to the corresponding o-benzoquinone at room temperature and displaying catalase activity for the hydrogen peroxide dismutation with remarkable activity (TON up to 4000)

In this communication we propose a convenient methodology to effect the oxidation of alkynes using ammonium persulfate and diphenyl diselenide as catalyst. The reactions effected in aqueous media lead to 1,2-unprotected dicarbonyl derivatives or to hemiacetals starting from terminal alkynes.