CuI/2,2'-联吡啶/2,2,6,6-四甲基哌啶氧化物催化氧化醇生成腈的工艺

以高压反应釜为反应装置,采用CuI/Bipy(2,2'-联吡啶)/TEMPO(2,2,6,6-四甲基哌啶氧化物)催化体系,以氨水作氮源,分子氧作氧化剂,对醇催化氧化生成相应腈的方法进行了优化。 以苯甲醇的催化氧化反应为模型反应,考察了催化剂及其用量、溶剂、反应温度以及时间对催化性能的影响。 实验表明:在高压釜中,120 ℃、40×10⁵ Pa的氮氧混合气(φ(O₂)=8%)条件下,将催化剂摩尔分数降低至1%(脂肪醇催化剂摩尔分数为5%),反应时间缩短至8 h时,催化效果最佳。同时,该反应系统对于不同的芳香醇和脂肪醇的氧化均取得了90%以上的转化率和90%以上的产品收率。     

Oxidative fragmentation of oxiranes to nitriles with hypervalent iodine(V) reagents in aqueous ammonia

Oxiranes undergo oxidative fragmentation when treated with hypervalent iodine(V) reagents particularly o-iodoxybenzoic acid in aqueous ammonia to give nitriles. The reaction goes via the formation of 1, 2-amino alcohols as intermediates followed by C-C bond cleavage.     

Direct Synthesis of Nitriles from Aldehydes Using Chloramine-T/KI in Aqueous Ammonia

A convenient method for direct conversion of aldehydes into nitriles has been developed using chloramine-T/KI in aqueous ammonia.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource: Full experimental and spectral details.]     

Direct oxidative conversion of alcohols and amines to nitriles with molecular iodine and DIH in aq NH3

Simple and high-yield procedures for the direct oxidative conversion of various primary alcohols, and primary, secondary, and tertiary amines to the corresponding nitriles were successfully carried out with molecular iodine in aq ammonia and 1,3-diiodo-5,5-dimethylhydantoin in aq NH₃, respectively.     

Direct oxidative conversion of aldehydes to nitriles using IBX in aqueous ammonia

A mild, simple, chemoselective and high yielding procedure for the direct oxidative conversion of aldehydes to nitriles has been developed using IBX in aqueous ammonia.     

Regioselective nucleophilic opening of epoxides and aziridines under neutral conditions in the presence of β-cyclodextrin in water

A variety of β-hydroxy nitriles and β-amino alcohols have been synthesized by the regioselective ring opening of epoxides and aziridines under neutral and aqueous conditions in the presence of β-cyclodextrin in good yields.     

A novel system for the synthesis of nitriles from aldehydes using aqueous ammonia and sodium dichloroiodate

A simple and mild method for the conversion of varieties of aldehydes to the corresponding nitriles using aqueous ammonia and aqueous sodium dichloroiodate reagent at room temperature is discussed. Advantages of this system are short reaction time, easy work-up and moderate to good yields.     

Powerful amide synthesis from alcohols and amines under aerobic conditions catalyzed by gold or gold/iron, -nickel or -cobalt nanoparticles

Considering the importance of the development of powerful green catalysts and the omnipresence of amide bonds in natural and synthetic compounds, we report here on reactions between alcohols and amines for amide bond formation in which heterogeneous gold and gold/iron, -nickel, or -cobalt nanoparticles are used as catalysts and molecular oxygen is used as terminal oxidant. Two catalysts show excellent activity and selectivity, depending on the type of alcohols used. A wide variety of alcohols and amines, including aqueous ammonia and amino acids, can be used for the amide synthesis. Furthermore, the catalysts can be recovered and reused several times without loss of activity.     

Microwave-assisted one-pot tandem reactions for direct conversion of primary alcohols and aldehydes to triazines and tetrazoles in aqueous media

A series of primary alcohols and aldehydes were treated with iodine in ammonia water under microwave irradiation to give the intermediate nitriles, which without isolation underwent [2+3] cycloadditions with dicyandiamide and sodium azide to afford high yields of the corresponding triazines and tetrazoles, including the alpha-amino- and dipeptidyl tetrazoles in high optical purity.     

(P2O5/SiO2): a useful heterogeneous alternative for the Ritter reaction

Tertiary alcohols as well as primary and secondary benzylic alcohols react efficiently with nitriles to give the corresponding amides in good to excellent yields in the presence of P₂O₅/SiO₂ (60% w/w).     

One-step conversion of alcohols into nitriles with simultaneous two-carbon chain elongation. (Cyanomethyl)trimethylphosphonium iodide as a reagent with a dual mode of action

Treatment of alcohols with an excess of (cyanomethyl)trimethylphosphonium iodide leads, after aqueous hydrolysis, to the clean formation of nitriles with two more carbon atoms than present in the original alcohol. Benzylic, allylic, and aliphatic alcohols without beta-branching (RCH(2)CH(2)OH) have been converted to nitriles with success. The required phosphonium iodide is simple to prepare and can be stored for a long time at room temperature.     

Synthesis of β-hydroxy nitriles and 1,3-amino alcohols from epoxides using acetone cyanohydrin as a LiCN precursor

The reaction of acetone cyanohydrin with MeLi affords a LiCN·acetone complex that can be made to react with epoxides in THF, either in one-pot or using isolated samples of the cyanide complex, to cleanly afford β-hydroxy nitriles upon aqueous workup; in situ hydride reduction of nitriles affords 1,3-amino alcohols.     

Polymer‐anchored Ru(II) complex as an efficient catalyst for the synthesis of primary amides from nitriles and of secondary amides from alcohols and amines

A polymer‐anchored ruthenium(II) catalyst was synthesized and characterized. Its catalytic activity was evaluated for the preparation of primary amides from aqueous hydration of nitriles in neutral condition. A range of nitriles were successfully converted to their corresponding amides in good to excellent yields. The catalyst was also effective in the preparation of secondary amides from the coupling of alcohols and amines. The catalyst can be facilely recovered and reused six times without a significant decrease in its activity. Copyright © 2014 John Wiley & Sons, Ltd.     

Palladium-catalyzed oxidation of lower aliphatic alcohols with oxygen in the presence of aromatic nitriles in aqueous medium

The kinetics of oxidation of lower aliphatic alcohols (C₁–C₄) to the corresponding carbonyl compounds with oxygen in the presence of palladium(II) tetraaqua complex and aromatic nitriles (benzonitrile, phenylacetonitrile, and o-tolunitrile) in aqueous medium (c = 0.01 M) at 65°C under atmospheric pressure were studied. A probable reaction mechanism and kinetic equation were proposed. Aromatic nitriles were found to stabilize decomposition of low-valence palladium species, ensuring activation of molecular oxygen and subsequent oxidation of alcohols.     

Direct synthesis of nitriles from aldehydes using tetrabutylammonium tribromide in aqueous ammonia

Abstract  

A convenient method for direct conversion of aldehydes into nitriles has been developed by using tetrabutylammonium tribromide in aqueous ammonia.     

Synthesis of alkyl iodides/nitriles from carbonyl compounds using novel ruthenium tris(2,2,6,6-tetramethyl-3,5-heptanedionate) as catalyst

Aldehydes and ketones were hydrogenated to the corresponding alcohols, which were then transformed in situ into their respective iodides and nitriles in good yields. A structurally well-defined O-containing transition metal complex, Ru (TMHD)₃, was found to be the active catalyst for hydrogenation, iodination and cyanation reactions. It has high affinity for the transformation of benzylic alcohols to iodides and nitriles.     

Novel System for the Synthesis of Nitriles from Aldehydes Using Aqueous Ammonia and [Bis(Trifluoroacetoxy)iodo]benzene

A simple and mild method for the conversion of varieties of aldehydes to the corresponding nitriles using aqueous ammonia and trivalent hypervalent iodine reagent, [bis(trifluoroacetoxy)iodo]benzene, at room temperature is discussed. Advantages of this system are short reaction time, easy workup, and moderate to good yields.     

FeCl3-catalyzed Ritter reaction. Synthesis of amides

A safe and inexpensive synthesis of amides, from benzylic alcohols and nitriles and from t-butyl acetate and nitriles, using a Ritter reaction catalyzed by FeCl₃·6H₂O is described.     

Facile preparation of alpha-aryl nitriles by direct cyanation of alcohols with TMSCN under the catalysis of InX3

A convenient and efficient synthesis of alpha-aryl nitriles was developed by direct cyanation of alcohols with TMSCN under the catalysis of Lewis acid. Using 5-10 mol % of InBr3 as the catalyst, a variety of benzylic alcohols can be converted to the corresponding nitriles in 5-30 min with yields of 46-99%.     

Chemoselective hydrogenation of nitriles to primary amines catalyzed by water‐soluble transition metal catalysts

The water‐soluble rhodium complex generated in situ from [Rh (COD)Cl]₂ in aqueous ammonia has been revealed as a highly efficient catalyst for the hydrogenation of aromatic nitriles, to primary amines with excellent yields. The catalyst is also highly selective towards primary amines in the case of sterically hindered aliphatic nitriles. The catalytic system can also be recycled and re‐used with no significant loss of activity.