A new and efficient catalytic hydrolysis of aliphatic and aromatic thiolates under ambient conditions is presented. Previously, we have demonstrated (Ganguly et al., Inorg. Chem. 2018, 57, 11306–11309) the Co­(II) mediated stoichiometric hydrolysis of thiols to produce alcohols/phenols along with a binuclear dicobalt­(II)-hydrosulfide complex, [Co2(PhBIMP)­(μ2-SH)­(DMF)]2+ (1) (PhBIMP is the anion of 2,6 bis­[(bis­((N-1-methyl-4,5- diphenylimidazoylmethyl) amino)­methyl]- 4-methylphenol). In the present work, we have shown that the product of the stoichiometric reaction, 1, may act as an efficient catalyst for the catalytic hydrolysis of a broad range of aliphatic and aromatic thiolates in DMF at room temperature to produce alcohols/phenols. Complex 1 takes up a thiolate (RS–) and a water molecule to generate an active intermediate complex, [Co2(PhBIMP)­(μ2-SH)­(RS)­(H2O)]1+ (2), which, in turn, releases the alcohol/phenol (ROH), hydrosulfide (HS–), and regenerates 1.

An iron­(II)-benzilate complex [(TPASH)­FeII­(benzilate)]­ClO4@­C8Au (2) (TPASH = 11-((6-((bis­(pyridin-2-yl­methyl)­amino)­methyl)­pyridin-2-yl)­meth­oxy)­undecane-1-thiol) immobilized on octanethiol stabilized gold nanoparticles (C8Au) of core diameter less than 5 nm has been prepared to evaluate its reactivity toward O2-dependent oxidations compared to a nonimmobilized complex [(TPA-O-Allyl)­FeII­(benzilate)]­ClO4 (1a) (TPA-O-Allyl = N-((6-(allyl­oxy­methyl)­pyridin-2-yl)­methyl)­(pyridin-2-yl)-N-(pyridin-2-ylmeth­yl)­methan­amine). X-ray crystal structure of the nonimmobilized complex 1a reveals a six-coordinate iron­(II) center in which the TPA-O-Allyl acts as a pentadentate ligand and the benzilate anion binds in monodentate fashion. Both the complexes (1a and 2) react with dioxygen under ambient conditions to form benzophenone as the sole product through decarboxylation of the coordinated benzilate. Interception studies reveal that a nucleophilic iron-oxygen intermediate is formed in the decarboxylation reaction. The oxidants from both the complexes are able to carry out oxo atom transfer reactions. The immobilized complex 2 not only performs faster decarboxylation but also exhibits enhanced reactivity in oxo atom transfer to sulfides. Importantly, the immobilized complex 2, unlike 1a, displays catalytic turnovers in sulfide oxidation. However, the complexes are not efficient to carry out cis-dihydroxylation of alkenes. Although the immobilized complex yields a slightly higher amount of cis-diol from 1-octene, restricted access of dioxygen and substrates at the coordinatively saturated metal centers of the complexes likely makes the resulting iron-oxygen species less active in oxygen atom transfer to alkenes. The results implicate that surface immobilized nonheme iron complexes containing accessible coordination sites would exhibit better reactivity in O2-dependent oxygenation reactions.

Poly(amidoamine) dendrimers grafted on carbon nanotubes have been appended with iron(II)‐α‐keto acid (benzoylformate) complex of polypyridyl ligand to design artificial non‐heme oxygenase model. This nano‐enzyme was applied for selective catalytic oxidation of organic molecules. Although the carbon nanotubes serve as a robust heterogeneous platform, the amine terminals of dendrimers provide catalysts binding sites and the amide bonds provide a necessary second coordination sphere similar to the enzymatic polypeptide chains. Such a hybrid design prevented the deactivation of the primary active sites leading to 8 times faster oxidative decarboxylation rates than those of its homogeneous analogue. An electrophilic iron(IV)‐oxo intermediate has been intercepted, which catalyzes the selective oxidation of alcohols to aldehydes and incorporates single oxygen atoms into sulfides and olefins by using aerial oxygen with multiple turnover numbers. The catalyst was consecutively regenerated three times by mild chemical treatment and showed negligible loss of activity.

Four cobalt(II)-carboxylate complexes [(6-Me3-TPA)CoII(benzoate)](BPh4) (1), (6-Me3-TPA)CoII(benzilate)](ClO4) (2), [(6-Me3-TPA)CoII(mandelate)](BPh4) (3), and [(6-Me3-TPA)CoII(MPA)](BPh4) (4) (HMPA = 2-methoxy-2-phenylacetic acid) of the 6-Me3-TPA (tris((6-methylpyridin-2-yl)methyl)amine) ligand were isolated to investigate their ability in H2O2-dependent selective...

Two mononuclear nonheme iron(II)-benzoylformate (BF) complexes [(6Me2-Me-BPA)Fe(BF)](ClO4) (1a) and [(6Me3-TPMM)Fe(BF)](ClO4) (1b) of tridentate nitrogen donor ligands, bis((6-methylpyridin-2-yl)methyl)(N-methyl)amine (6Me2-Me-BPA) and tris(2-(6-methyl)pyridyl)methoxymethane (6Me3-TPMM), were isolated and characterized. The structural characterization of iron(II)-chloro...