Nitrile Hydrolysis Promoted by Rhenium(III) Metal-Metal Bonded Systems

Eglin, Judith L.

doi:10.1080/02603590214378

“…16,40 Addition of 1 mmol (100 mol%, 0.33 M) NaCl to the hydration of benzonitrile resulted in a slight decrease in conversion from 99 to 93% after 7 h. 41 This is in contrast to a Pd nanoparticle system in which addition of 5 mol% chloride ion (0.02 M) reduces nitrile hydration conversion from 87 to 2.7%. 42 Further evidence for the robust nature of the catalyst was obtained upon storing an aqueous solution of [RuCl 2 (PTA) 4 ] under air for four weeks at~0 • C. Hydration of benzonitrile performed using the stored aqueous solution of [RuCl 2 (PTA) 4 ] (1 mol% loading) resulted in a 83% conversion after 7 h compared to 87% by freshly-prepared catalyst in water; both reactions reached >99% conversion by 24 h.…”

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confidence: 93%

“…28,29 31 P{ 1 H} NMR spectroscopy was obtained on the reaction mixture after 2 h in attempt to identify active species in water. 32 4 ] by our group. 38 The durability of [RuCl 2 (PTA) 4 ] was evaluated by reducing the catalyst loading (Table 2).…”

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confidence: 99%

“…9-12, 27 The superior activity of [RuCl 2 (h 6 -benzene)(PTA)], where PTA = 1,3,5-triaza-7-phosphaadamantane, over [RuCl 2 (h 6 -benzene)(PPh 3 )], was attributed to the cooperative effect of the PTA amine functionality activating water via hydrogen bonding. Cadierno's work prompted us to investigate the catalytic activity of [RuCl 2 (PTA) 4 ] for nitrile hydration compared with the inactive [RuCl 2 (PPh 3 ) 3 ] analogue. Darensbourg, Joó, and co-workers 28 first synthesized the air-stable and water-soluble [RuCl 2 (PTA) 4 ] and utilized it as a catalyst for the hydrogenation of aldehydes, 28 olefins, 28 and CO 2 29 in aqueous or biphasic media.…”

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confidence: 99%

“…Darensbourg, Joó, and co-workers 28 first synthesized the air-stable and water-soluble [RuCl 2 (PTA) 4 ] and utilized it as a catalyst for the hydrogenation of aldehydes, 28 olefins, 28 and CO 2 29 in aqueous or biphasic media. Herein we describe the hydration of various nitriles to their corresponding amides in aqueous and biphasic media by the air-stable, water-soluble, efficient, and recyclable catalyst: [RuCl 2 (PTA) 4 ].…”

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confidence: 99%

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Aqueous and biphasic nitrile hydration catalyzed by a recyclable Ru(ii) complex under atmospheric conditions

Lee

¹

,

Frost

²

2012

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RuCl 2 (PTA) 4 ] (PTA = 1,3,5-triaza-7-phosphaadamantane) was found to be a highly active catalyst for aqueous phase nitrile hydration at 100 • C in air. Near quantitative conversion of aromatic, alkyl, and vinyl nitriles to their corresponding amides was observed. The reaction tolerated ether, hydroxyl, nitro, bromo, formyl, pyridyl, benzyl, alkyl, and olefinic functional groups. Some amides were isolated by simple decantation from the aqueous phase catalyst. Catalyst loading down to 0.001 mol% was examined with turnover numbers as high as 22 000 observed. The catalyst was stable for weeks in solution and could be reused more than five times without significant loss of activity.Amides are versatile and important synthetic intermediates used in the production of a variety of plastics, detergents, lubricants, and polymers. 1,2 Traditional methods of hydrating nitriles to amides involve the use of strong bases or acids under harsh conditions, often inducing undesired hydrolysis to carboxylic acids. 1-5 During neutralization salt formation can lead to contamination, separation, and pollution problems. 1-3 Moreover, poor tolerance for sensitive functional groups is often observed under such conditions. 1-3 A variety of transition metal complexes have been developed as efficient catalysts for nitrile hydration in organic media often with air-sensitive or non-recyclable catalysts. 1-7 Water, with its unique properties, has seen increased use as a solvent in stoichiometric and catalytic reactions. 8 Recently several aqueous homogeneous 9-11 and heterogeneous 12-15 nitrile hydration reactions have been reported under inert atmosphere.One common mechanistic pathway proposed for the hydration of nitriles involves nitrile coordination to a metal followed by nucleophilic attack by water on the nitrile carbon. 1 Recent studies have shown that nucleophilic attack can be promoted by activating water via hydrogen bonding to a functionalized ligand. 9-12,16-18 † Electronic supplementary information (ESI) available: Experimental details including nitrile hydration and catalyst recycling procedures, 31 P{ 1 H} NMR spectrum of the reaction mixture, and GC chromatogram, 1 H and 13 C{ 1 H} NMR spectra of isolated amides. See

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“…54 Redox potential-electronic structure relationships in 18-and 17-electron mononitrile complexes of Re have been established. 55 It was possible to estimate, for the nitrile and related ligands, for example, in complexes (3)(4)(5)(6), the values of the electrochemical P L ligand parameter, a measure of the net electron donor minus π -acceptor character of a ligand.…”

Section: Complexes With Group 15 Elementsmentioning

confidence: 99%

Technetium & Rhenium: Inorganic & Coordination Chemistry

Pombeiro¹,

Silva²,

Crabtree

³

2005

Encyclopedia of Inorganic and Bioinorganic Chemistry

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The inorganic and coordination chemistry of both rhenium and technetium is described in a condensed way with presentation of significant and typical compounds and reactions and applications in nuclear medicine and catalysis. After an Introduction, with properties of those elements and their sources, a description of binary compounds (for example oxides, sulfides, halides, and nitrides), their syntheses, structures, and selected reactions are given. This is followed by a treatment of the coordination chemistry of those metals, comprising hydrides, metal–metal bonded species and complexes with ligands coordinated by donor‐atoms mainly of the following periodic groups: 15 (commonly nitrogen and phosphorus, including dinitrogen, nitrile, nitric oxide and related ligands, hydrazides, diazenides, nitride, imides, pyrazolylborates, and phosphine ligands), 16 (mainly oxo, thio, and other O‐ or S‐ligands), and 17 (halide ligands); the metal–carbon (group 14) bond complexes are usually not covered since they are dealt with separately. Preparative methods, structures, and reactivities are illustrated for those types of complexes. Selected complexes of 99 m Tc and 186 Re (or 188 Re) are described and their applications in nuclear medicine illustrated, as radiopharmaceuticals normally for clinical diagnosis. The application of inorganic rhenium complexes in catalysis constitutes a currently expanding area of high potential and their use as catalysts for the following reactions is reviewed: oxygen atom transfer (OAT) and related reactions; isomerization or etherification of allylic or propargylic alcohols; Beckmann rearrangement of oximes; dehydration of primary amides and aldoximes; dehydrogenation of alkanes, unconventional reduction of aldehydes and ketones; aldol‐type reactions; and photo‐ and electrocatalytic reduction of carbon dioxide. A few catalytic applications of technetium compounds are also indicated.

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Technetium & Rhenium: Inorganic & Coordination Chemistry

Pombeiro¹,

Silva²,

Crabtree

³

2005

Encyclopedia of Inorganic Chemistry

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The inorganic and coordination chemistry of both rhenium and technetium is described in a condensed way with presentation of significant and typical compounds and reactions and applications in nuclear medicine and catalysis. After an Introduction, with properties of those elements and their sources, a description of binary compounds (for example oxides, sulfides, halides, and nitrides), their syntheses, structures, and selected reactions are given. This is followed by a treatment of the coordination chemistry of those metals, comprising hydrides, metal–metal bonded species and complexes with ligands coordinated by donor‐atoms mainly of the following periodic groups: 15 (commonly nitrogen and phosphorus, including dinitrogen, nitrile, nitric oxide and related ligands, hydrazides, diazenides, nitride, imides, pyrazolylborates, and phosphine ligands), 16 (mainly oxo, thio, and other O‐ or S‐ligands), and 17 (halide ligands); the metal–carbon (group 14) bond complexes are usually not covered since they are dealt with separately. Preparative methods, structures, and reactivities are illustrated for those types of complexes. Selected complexes of 99 m Tc and 186 Re (or 188 Re) are described and their applications in nuclear medicine illustrated, as radiopharmaceuticals normally for clinical diagnosis. The application of inorganic rhenium complexes in catalysis constitutes a currently expanding area of high potential and their use as catalysts for the following reactions is reviewed: oxygen atom transfer (OAT) and related reactions; isomerization or etherification of allylic or propargylic alcohols; Beckmann rearrangement of oximes; dehydration of primary amides and aldoximes; dehydrogenation of alkanes, unconventional reduction of aldehydes and ketones; aldol‐type reactions; and photo‐ and electrocatalytic reduction of carbon dioxide. A few catalytic applications of technetium compounds are also indicated.

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Nitrile Hydrolysis Promoted by Rhenium(III) Metal-Metal Bonded Systems

Abstract: The ability to hydrolyze nitriles to form coordinated amidate ligands has recently been demonstrated using Related. The significance of nitrile hydrolysis reactions, proposed reaction mechanism, and potential applications of this type of reaction are reviewed.

Cited by 50 publications

References 86 publications

Aqueous and biphasic nitrile hydration catalyzed by a recyclable Ru(ii) complex under atmospheric conditions

Aqueous and biphasic nitrile hydration catalyzed by a recyclable Ru(ii) complex under atmospheric conditions

Technetium & Rhenium: Inorganic & Coordination Chemistry

Technetium & Rhenium: Inorganic & Coordination Chemistry

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