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In this paper we report the preparation of catalytic polymeric membranes having the complex [( N,N ′- bis (3- tert -butyl-5-(heptadecafluorooctyl)salicylidene)- trans -1,2-cyclohexanediamine)Co] embedded into Hyflon AD60X, PES and PSf and their use in the cyclopropanation reaction of olefins with ethyl diazoacetate (EDA). A study of the reaction in the homogeneous phase was also performed. The kinetics of the cyclopropanation reaction is first-order in the diazoacetate and the catalyst and zero order in the olefin, but we observed a more complex dependence on the additive, NMI ( N -methylimidazole). The positive effect of the additive is completely reversed at NMI concentration higher than 6·10 −2 M.

The addition of Ru3(CO)12, dimethyl carbonate, or both to the reaction mixture improves the selectivity of the palladium/phenanthroline-catalyzed reaction of nitroarenes, arylalkynes, and CO to give 3-arylindoles. When 4-fluorophenylacetylene and nitrobenzene are used as substrates, the indole skeleton of Fluvastatin and other pharmaceutically active compounds is obtained in one step.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

New transition metal complexes of CoII, CuII, NiII and VIVO with the Schiff base, HL, 3-acetylcoumarin-N(4)-phenylthiosemicarbazone have been prepared. Characterisation of the HL ligand and its complexes is also reported. Mass spectra and NMR assignments for the ligand, using COSY, NOESY homonuclear and HMQC and HMBC heteronuclear correlation techniques were carried out. Electronic and magnetic moments of the complexes indicate that the geometries of the metal centres are either distorted octahedral, square pyramidal, square planar or tetrahedral. The structures are consistent with the IR, UV–Vis, ESR, as well as conductivity and magnetic moments measurements. Cyclopropanation reactions of unactivated olefins by ethyldiazoacetate (EDA) in the presence of LCuIICl as catalyst proceed with excellent TON (up to 9625).

Herein we report the one-pot synthesis of several N-heterocyclic compounds by rearrangement reactions of N-aryl-2-vinylaziridines. The optimization of the synthetic methodology employed allowed us to obtain differently substituted 2,5-dihydro-1H-benzo[b]azepines in good yields and purities. The relationship between the nature of the starting N-aryl-2-vinylaziridine and the obtained N-heterocycle was also investigated. Finally, to rationalize all the experimental results reported in this paper a theoretical study was performed that casts light on the reaction mechanism.

Cobalt(II) complexes of chiral bis-binaphthyl porphyrins were prepared, and their catalytic activity in the asymmetric cyclopropanation of alkenes with ethyl diazoacetate was examined. Good yields and enantioselectivities (up to 90% ee) were observed with cis/trans ratios reaching 11:89. UV−vis and 1H NMR studies suggest that the axial nitrogen ligand N-methylimidazole could play a role in changing the enantioselectivity of the reaction.

In this paper we report the preparation of catalytic membranes having the complex Ru(4-(CF3)TPP)CO (1) (TPP = dianion of tetraphenylporphyrin) embedded in the perfluorinated polymer Hyflon AD60X and their use in the aziridination reaction of olefins by aryl azides. The heterogeneous membrane catalysts afforded high selectivities in aziridine (90–99%). In several cases the membrane was reused three times with a catalyst leaching ≤6% but no decrease in selectivities upon recycle was observed.

Aryl azides have been used as atom-efficient nitrene transfer reagents in the (porphyrin)ruthenium-catalyzed amination of olefins. Several azides, olefins and [Ru(porphyrin)CO] complexes were tested to investigate the scope and limits of the reaction. Quantitative yields and short reaction times were achieved by using terminal olefins and aryl azides bearing electron-withdrawing groups on the aryl moiety. The reactions were influenced by steric factors. Internally disubstituted olefins exhibited a lower reactivity and tri- and tetrasubstituted olefins did not react at all. A very high turnover number (TON) for the [Ru(TPP)CO] (TPP = tetraphenylporphyrin dianion) catalyzed amination of α-methylstyrene by p-nitrophenyl azide was obtained.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

[Ru(CO)(porphyrin)] complexes have been found to catalyze the direct aziridination of conjugated dienes by aryl azides with high chemoselectivity, to provide N-aryl-2-vinylaziridines. To determine the scope of the reaction, several hydrocarbons and azides were tested. The reactions between 2,3-dimethylbuta-1,3-diene and aryl azides bearing electron-withdrawing groups in the para or meta positions in their aryl moieties occur very efficiently in short times, while the selectivities of the aziridinations are governed by the steric hindrances of the double bonds, so lower yields are registered with sterically encumbered 1,4-disubstituted dienes, though it is worth noting that the aziridination of trans,trans-1,4-diphenylbuta-1,3-diene was stereospecific and that only one isomer was obtained. The aza-[3,3]-Claisen rearrangement of 2-isopropenyl-2-methyl-N-(4-nitrophenyl)aziridine to produce the corresponding 2,5-1H-benzo[b]azepine is also reported.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

Fluorides promote the palladium–phenanthroline catalyzed carbonylation of nitroarenes to carbamates. The effect is more evident on the rate of the reaction at short reaction times, but a positive effect on selectivity is also observed under certain conditions. The effect is observed even under conditions under which chloride inhibits the reaction. Tetraethylammonium is a better countercation than sodium. Copyright © 2007 John Wiley & Sons, Ltd.

The interaction of organic azides with transition metal complexes will be discussed with particular attention to the coordination modes of these molecules. The stoichiometric reactions of organic azides with coordinated ligands will be considered and their use in amination reactions catalyzed by transition metal complexes will be discussed in detail. The utility of these catalytic reactions for the synthesis of organic compounds will be stressed.

A reproducible synthesis of a competent epoxidation catalyst, [Ru(VI)(TPP)(O)2)] (TPP = tetraphenylporphyrin dianion), starting from [Ru(II)(TPP)(CO)L] (L = none or CH3OH), is described. The molecular structure of the complex was determined by using ab initio X-ray powder diffraction (XRPD) methods, and its solution behavior was in detail investigated by NMR techniques such as PGSE (pulsed field gradient spin-echo) measurements. [Ru(IV)(TPP)(OH)]2O, a reported byproduct in the synthesis of [Ru(VI)(TPP)(O)2], was synthesized in a pure form by oxidation of [Ru(II)(TPP)(CO)L] or by a coproportionation reaction of [Ru(VI)(TPP)(O)2] and [Ru(II)(TPP)(CO)L], and its molecular structure was then determined by XRPD analysis. [Ru(VI)(TPP)(O)2] can be reduced by dimethyl sulfoxide or by carbon monoxide to yield [Ru(II)(TPP)(S-DMSO)2] or [Ru(II)(TPP)(CO)(H2O)], respectively. These two species were characterized by conventional single-crystal X-ray diffraction analysis.

Nitrene transfer reactions represent a useful methodology to synthesize in a few steps high added-value compounds used as organic intermediates. Herein, we describe the catalytic activity of metal porphyrin complexes in a wide range of reactions such as C–H hydrocarbon amination and olefin aziridination to synthesize nitrogen containing molecules. All the most important nitrene sources have been reviewed stressing the potentiality and limits of each one in the particular class of chemical transformation.

The complex Ru(TPP)(NAr)(2) inserts a nitrene group into allylic and benzylic C-H bonds and is the key intermediate in the ruthenium porphyrin-catalyzed amination of hydrocarbons by aryl azides.

Nitrene transfer reactions represent a useful methodology to synthesize in a few steps high added-value compounds used as organic intermediates. Herein, we describe the catalytic activity of metal porphyrin complexes in a wide range of reactions such as C–H hydrocarbon amination and olefin aziridination to synthesize nitrogen containing molecules. All the most important nitrene sources have been reviewed stressing the potentiality and limits of each one in the particular class of chemical transformation.

Aryl azides have been used as atom-efficient nitrene transfer reagents in the (porphyrin)ruthenium-catalyzed amination of olefins. Several azides, olefins and [Ru(porphyrin)CO] complexes were tested to investigate the scope and limits of the reaction. Quantitative yields and short reaction times were achieved by using terminal olefins and aryl azides bearing electron-withdrawing groups on the aryl moiety. The reactions were influenced by steric factors. Internally disubstituted olefins exhibited a lower reactivity and tri- and tetrasubstituted olefins did not react at all. A very high turnover number (TON) for the [Ru(TPP)CO] (TPP = tetraphenylporphyrin dianion) catalyzed amination of α-methylstyrene by p-nitrophenyl azide was obtained.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

CoII(tpp) catalyzes the reaction of aromatic azides (ArN3) with nonactivated olefins to yield allylic amines or aziridines in moderate-to-good yields. The chemoselectivity of the catalytic reaction is particularly high. Depending on the substrate employed, allylic amines or aziridines can be obtained. The reaction mechanism was investigated, and the reaction proceeds through reversible coordination of the aryl azide to the CoII–porphyrin complex. The often postulated “nitrene” complex is not an intermediate in this reaction. The kinetics for the allylic amination is first order in azide, Co(tpp), and olefin. For the aziridination, the kinetics is again first order in azide and catalyst, but we observed a first-order dependence of the rate on α-methylstyrene only up to an olefin concentration of 6.9 M. An inhibiting role of the competitively formed 1-(4-nitrophenyl)-5-methyl-5-phenyl-1,2,3-triazoline was identified. The triazoline was shown to reversibly coordinate to Co(tpp), which blocks the free coordination site necessary for the catalytic reaction to proceed, and is it responsible for the catalyst deactivation in the aziridination reaction of α-methylstyrene by 4-nitrophenyl azide. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)

[Ru(CO)(porphyrin)] complexes have been found to catalyze the direct aziridination of conjugated dienes by aryl azides with high chemoselectivity, to provide N-aryl-2-vinylaziridines. To determine the scope of the reaction, several hydrocarbons and azides were tested. The reactions between 2,3-dimethylbuta-1,3-diene and aryl azides bearing electron-withdrawing groups in the para or meta positions in their aryl moieties occur very efficiently in short times, while the selectivities of the aziridinations are governed by the steric hindrances of the double bonds, so lower yields are registered with sterically encumbered 1,4-disubstituted dienes, though it is worth noting that the aziridination of trans,trans-1,4-diphenylbuta-1,3-diene was stereospecific and that only one isomer was obtained. The aza-[3,3]-Claisen rearrangement of 2-isopropenyl-2-methyl-N-(4-nitrophenyl)aziridine to produce the corresponding 2,5-1H-benzo[b]azepine is also reported.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

The reaction of Ru(TPP)CO (TPP = dianion of tetraphenylporphyrin) with 1-(p-nitrophenyl)-5-methyl-5-phenyl-1,2,3-triazoline yielded a Δ2-1,2,3-triazoline ruthenium(II) porphyrin complex, which is responsible for the catalyst deactivation in the aziridination reaction of α-methylstyrene by p-nitrophenyl azide.

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