Nickel amide

Plastics Additives. Many claims have been made for the use of nickel chemicals as additives to various resin systems. By far the most important appHcation is as uv-quenchers in polyolefins (173,174). Among the useful nickel complexes in these systems are dibutyldithiocarbamate nickel [13927-77-0], nickel thiobisphenolates, and nickel amide complexes of bisphenol sulfides (175). The nickel complex of... 

In the system nickel/L/butadiene, secondary amines can shift the cyclodimerization of butadiene to the acyclic products (7a) and (75) Its cocatalyst functfon can be visualized by the corresponding [L]-control map (Scheme 3.3-2). In the three-component system nickel/morpholine/butadiene the open-chain products are formed for log ([morpholine]o/[Ni]o) > -1. Both octatrienes (7a) and (75) are formed at the constant ratio of 1.8 over the entire range of the examined amine/nickel scale. However, the efficiency of the catalytic system is low. After a turnover of 30% butadiene, the catalytic activity ends because of the formation of stop complexes of the nickel amide type. 

Ni3N2 has been observed as the thermal decomposition product of nickel amide between 120 and 360 °C before it decomposes to Ni3N (analogous to cobalt). Ni3N2 is amorphous to X-ray diffraction [87, 350]. It has also been prepared from a reaction of NiCl2 and ammonia at 500 °C as shown by IR [351]. 

As already mentioned, reactive nickel amide, hydroxo, or alkoxo complexes can experience insertion reactions giving rise to new Ni-G bonds. The mononuclear anilido complex 114 reacts with dimethyl acetylenedicarboxylate, resulting in the formation of the alkenyl complex 151 (Equation (74)). The insertion of GO into the Ni-N bond of an unusual tricoordinated Ni(ii) amido complex yields a carbamoyl ligand that features an unprecedented rf -C,0... 

Adiponitrile undergoes the typical nitrile reactions, eg, hydrolysis to adipamide and adipic acid and alcoholysis to substituted amides and esters. The most important industrial reaction is the catalytic hydrogenation to hexamethylenediarnine. A variety of catalysts are used for this reduction including cobalt—nickel (46), cobalt manganese (47), cobalt boride (48), copper cobalt (49), and iron oxide (50), and Raney nickel (51). An extensive review on the hydrogenation of nitriles has been recendy pubUshed (10). 

The zwitterion (6) can react with protic solvents to produce a variety of products. Reaction with water yields a transient hydroperoxy alcohol (10) that can dehydrate to a carboxyUc acid or spHt out H2O2 to form a carbonyl compound (aldehyde or ketone, R2CO). In alcohoHc media, the product is an isolable hydroperoxy ether (11) that can be hydrolyzed or reduced (with (CH O) or (CH2)2S) to a carbonyl compound. Reductive amination of (11) over Raney nickel produces amides and amines (64). Reaction of the zwitterion with a carboxyUc acid to form a hydroperoxy ester (12) is commercially important because it can be oxidized to other acids, RCOOH and R COOH. Reaction of zwitterion with HCN produces a-hydroxy nitriles that can be hydrolyzed to a-hydroxy carboxyUc acids. Carboxylates are obtained with H2O2/OH (65). The zwitterion can be reduced during the course of the reaction by tetracyanoethylene to produce its epoxide (66). 

Conversion of the nitrile to the amide has been achieved by both chemical and biological means. Several patents have described the use of modified Raney nickel catalysts ia this appHcation (25,26). Also, alkaH metal perborates have demonstrated their utiHty (27). Typically, the hydrolysis is conducted ia the presence of sodium hydroxide (28—31). Owiag to the fact that the rate of hydrolysis of the nitrile to the amide is fast as compared to the hydrolysis of the amide to the acid, good yields of the amide are obtained. Other catalysts such as magnesium oxide (32), ammonia (28,29,33), and manganese dioxide (34) have also been employed. 

Eatty amines are made by dehydration of amides to nitriles at 280—330°C, followed by hydrogenation of the nitrile over nickel or cobalt catalysts ... 

Most ring syntheses of this type are of modern origin. The cobalt or rhodium carbonyl catalyzed hydrocarboxylation of unsaturated alcohols, amines or amides provides access to tetrahydrofuranones, pyrrolidones or succinimides, although appreciable amounts of the corresponding six-membered heterocycle may also be formed (Scheme 55a) (73JOM(47)28l). Hydrocarboxylation of 4-pentyn-2-ol with nickel carbonyl yields 3-methylenetetrahy-drofuranone (Scheme 55b). Carbonylation of Schiff bases yields 2-arylphthalimidines (Scheme 55c). The hydroformylation of o-nitrostyrene, subsequent reduction of the nitro group and cyclization leads to the formation of skatole (Scheme 55d) (81CC82). 

Esters and amides are quite resistant to hydrogenation under almost all conditions so their presence is not expected to cause difficulties. Alkyl ethers and ketals are generally resistant to hydrogenolysis but benzyl ethers are readily cleaved, particularly over palladium or Raney nickel catalysts. ... 

Nickel peroxide is a solid, insoluble oxidant prepared by reaction of nickel (II) salts with hypochlorite or ozone in aqueous alkaline solution. This reagent when used in nonpolar medium is similar to, but more reactive than, activated manganese dioxide in selectively oxidizing allylic or acetylenic alcohols. It also reacts rapidly with amines, phenols, hydrazones and sulfides so that selective oxidation of allylic alcohols in the presence of these functionalities may not be possible. In basic media the oxidizing power of nickel peroxide is increased and saturated primary alcohols can be oxidized directly to carboxylic acids. In the presence of ammonia at —20°, primary allylic alcohols give amides while at elevated temperatures nitriles are formed. At elevated temperatures efficient cleavage of a-glycols, a-ketols... 

Condensation of the anion obtained on reaction of acetonitrile with sodium amide, with o-chlorobenzophenone (36), affords the hydroxynitrile, 37. Catalytic reduction leads to the corresponding amino alcohol (note that the benzhydryl alcohol is not hydrogenolyzed). Reductive alkylation with formaldehyde and hydrogen in the presence of Raney nickel gives the antitussive a-gent, chlorphedianol (39). °... 

A variety of catalysts including copper, nickel, cobalt, and the platinum metals group have been used successfully in carbonyl reduction. Palladium, an excellent catalyst for hydrogenation of aromatic carbonyls is relatively ineffective for aliphatic carbonyls this latter group has a low strength of adsorption on palladium relative to other metals (72,91). Nonetheless, palladium can be used very well with aliphatic carbonyls with sufficient patience, as illustrated by the difficult-to-reduce vinylogous amide I to 2 (9). 

Palladium complexes also catalyze the carbonylation of halides. Aryl (see 13-13), vinylic, benzylic, and allylic halides (especially iodides) can be converted to carboxylic esters with CO, an alcohol or alkoxide, and a palladium complex. Similar reactivity was reported with vinyl triflates. Use of an amine instead of the alcohol or alkoxide leads to an amide. Reaction with an amine, AJBN, CO, and a tetraalkyltin catalyst also leads to an amide. Similar reaction with an alcohol, under Xe irradiation, leads to the ester. Benzylic and allylic halides were converted to carboxylic acids electrocatalytically, with CO and a cobalt imine complex. Vinylic halides were similarly converted with CO and nickel cyanide, under phase-transfer conditions. ... 

P(0)(0Me)H and [TpAr Me]Zn0P(0)(0R)2, respectively (Scheme 26) (35). In addition, [TpAr Me]ZnOH also cleaves activated esters and amides in a stoichiometric fashion, as illustrated in Scheme 27. Kitajima has described a similar amide cleavage reaction between the copper and nickel hydroxide complexes [Tp JMtOH) (M = Ni, Cu) and p-nitroacetanilide to give [TpPr 2]M p2-MeC(0)NC6H4N02 [Eq. (34)] (198). 

The design and capacity of an RO unit is dependent upon the type of chemicals in the plating solution and the dragout solution rate. Certain chemicals require specific membranes. For instance, polyamide membranes work best on zinc chloride and nickel baths, and polyether/amide membranes are suggested for chromic acid and acid copper solutions. The flow rate across the membrane is very important. It should be set at a rate to obtain maximum product recovery. RO systems have a 95% recovery rate with some materials and with optimum membrane selection.22... 

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