Radical catalyzed debromination of bromo-alkanes by formate in aqueous solutions via a hydrogen atom transfer mechanism

Ni(I)(1,4,8,11-tetraazacyclotetradecane)(+), Ni(I)L(+), was produced in neutral aqueous solutions by radiolytic techniques. The mechanism and kinetics of the reaction of Ni(I)L(+) with maleate and fumarate were studied applying pulse-radiolysis and analysis of the final products. Surprisingly the mechanisms of reduction of maleate and fumarate differ considerably. Based on the results it was also shown that Ni(II)L(2+) is an electrocatalyst for the reduction of alkenes in aqueous solutions.

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“…In the N 2 O saturated solutions reaction ( 11) is followed by reaction (13) thus in these solutions the observed intermediate is…”

Section: Reactions Of Ni(i)l + With Maleatementioning

confidence: 99%

“…As Ni(II)L 2+ is used as electrocatalyst in debromination reactions 13 it was of interest to study its electrocatalytic characteristics towards alkene reductions in aqueous solutions.…”

Section: Electrochemical Reductions Of Alkenes By Ni(i)l + In Aqueous...mentioning

confidence: 99%

On the mechanism of reduction of maleate and fumarate by NiI(1,4,8,11-tetraazacyclotetradecane)+ in aqueous solutions

et al. 2010

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“…Shandalov et al. studied the reduction process of the divalent nickel complex using two methods, pulse radiolysis and electrochemistry, to obtain Ni(I)L + that in turn reduced the dissolved BBMP. It was found that one of the reduction products is bromide .…”

Section: Introductionmentioning

confidence: 99%

“…studied the reduction process of the divalent nickel complex using two methods, pulse radiolysis and electrochemistry, to obtain Ni(I)L + that in turn reduced the dissolved BBMP. It was found that one of the reduction products is bromide . This process was done by homogenous catalysis, where the lifetime of the monovalent nickel, which is formed by those methods, is short, as shown in the reactions mentioned above …”

Section: Introductionmentioning

confidence: 99%

Stabilization of Ni(I)(1,4,8,11‐tetraazacyclotetradecane)⁺ in a Sol‐Gel Matrix: It's Plausible Use in Catalytic Processes

Shamir¹,

Wolfer

Shames

et al. 2020

Israel Journal of Chemistry

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Monovalent nickel is used as a catalyst in a diversity of important chemical systems due to its properties as a strong reducing agent. However, monovalent nickel is unstable in homogeneous systems; its lifetime is very short, and therefore, its efficiency as a catalyst is quite limited. In this article, we demonstrate the catalytic capabilities of Ni(I)(1,4,8,11‐tetraazacyclotetradecane)+ as a reducing and catalytic agent by its entrapment in the silica sol gel matrix. The EPR results indicate that the sol‐gel matrix plays two roles: it inhibits the common mechanism of Ni(I)L+ decomposition in aqueous solutions, and it also facilitates its functionality as a heterogeneous catalyst, by stabilizing it for at least several hours. The activity of Ni(I)L+ which is entrapped within the matrix, was studied by reducing 2,2‐Bis(bromomethyl)‐1,3‐Propanediol and I3−. The results indicate that Ni(I)L+/Ni(III)L−H2+ acts as a good reducing agent. These results have important implications for a variety of essential catalytic reactions by shedding light on a new feature of sol‐gel matrices and their use as active species stabilizers.

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“…Ni II L i and Co II L i complexes, with suitable macrocyclic ligands, are reduced reversibly to relatively stable nickel(I) and cobalt(I) species, respectively, in aqueous solutions [8][9][10]. Nickel(I) macrocyclic complexes have attracted considerable attention because they enable the electrocatalytic reduction of alkyl halides [3,[11][12][13][14][15][16][17][18][19]. Furthermore, nickel complexes have recently increasingly been utilized as catalysts for ethylene polymerizations and oligomerizations [20].…”

Section: Introductionmentioning

confidence: 99%

On the mechanism of reduction of maleate by a Co(I) complex with a macrocylic ligand in aqueous solutions

Schutz

Masarwa

Zilbermann³

et al. 2010

Journal of Coordination Chemistry

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2010) On the mechanism of reduction of maleate by a Co(I) complex with a macrocylic ligand in aqueous solutionsRecently, it was shown that a Ni(I) complex with a tetraazamacrocyclic ligand (Ni I (1, 4, 8, 11-tetraazacyclotetradecane) þ , NiðIÞL þ 2 , cyclam), reduces maleate in aqueous solutions. It was decided to investigate whether this is a general reaction of low valent transition metal complexes. In this study, the reactions of Co I L þ (L ¼ 5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradeca-4,11-diene) with maleate were investigated. The effect of the addition of maleate to aqueous solutions containing this low valent metal complex, prepared via the pulse radiolysis technique, was studied. The d ! * complexes formed between the monovalent cobalt complex and maleate were detected and characterized by UV-Vis spectroscopy. The nature of the final products formed was studied and detailed mechanisms of the reduction processes are proposed. The mechanism and kinetics of the reaction of Co(I)L þ with maleate was studied applying pulse-radiolysis and analysis of the final products.

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Radical catalyzed debromination of bromo-alkanes by formate in aqueous solutions via a hydrogen atom transfer mechanism

Cited by 9 publications

References 10 publications

On the mechanism of reduction of maleate and fumarate by NiI(1,4,8,11-tetraazacyclotetradecane)+ in aqueous solutions

On the mechanism of reduction of maleate and fumarate by NiI(1,4,8,11-tetraazacyclotetradecane)+ in aqueous solutions

Stabilization of Ni(I)(1,4,8,11‐tetraazacyclotetradecane)⁺ in a Sol‐Gel Matrix: It's Plausible Use in Catalytic Processes

On the mechanism of reduction of maleate by a Co(I) complex with a macrocylic ligand in aqueous solutions

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Radical catalyzed debromination of bromo-alkanes by formate in aqueous solutions via a hydrogen atom transfer mechanism

Cited by 9 publications

References 10 publications

On the mechanism of reduction of maleate and fumarate by NiI(1,4,8,11-tetraazacyclotetradecane)+ in aqueous solutions

On the mechanism of reduction of maleate and fumarate by NiI(1,4,8,11-tetraazacyclotetradecane)+ in aqueous solutions

Stabilization of Ni(I)(1,4,8,11‐tetraazacyclotetradecane)+ in a Sol‐Gel Matrix: It's Plausible Use in Catalytic Processes

On the mechanism of reduction of maleate by a Co(I) complex with a macrocylic ligand in aqueous solutions

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Stabilization of Ni(I)(1,4,8,11‐tetraazacyclotetradecane)⁺ in a Sol‐Gel Matrix: It's Plausible Use in Catalytic Processes