Nickel carbonyl derivatives

Active Raney nickel induces desulfurization of many sulfur-containing heterocycles thiazoles are fairly labile toward this ring cleavage agent. The reaction occurs apparently by two competing mechanisms (481) in the first, favored by alkaline conditions, ring fission occurs before desul-, furization, whereas in the second, favored by the use of neutral catalyst, the initial desulfurization is followed by fission of a C-N bond and formation of carbonyl derivatives by hydrolysis (Scheme 95). 

Since the discovery of nickel carbonyl in 1890 (15), carbonyls of many other metals have been prepared. Nickel and iron are the only metals that combine direcdy with CO to produce carbonyls in reasonable yields. At least one carbonyl derivative is known for every t5 -block metal. A number of the neutral complexes that have been reported ate Hsted in Table 4. 

Garboxylation Reaction. The carboxylation reaction represents the conversion of acetylene and olefins into carboxyHc acids (qv) or their derivatives. The industrially important Reppe process is used in the synthesis of P-unsaturated esters from acetylene. Nickel carbonyl is the catalyst of choice (134). 

Reaction of l,3-bis(phenylmethyl)imidazol-2-ylidene with nickel tetra carbonyl gives [(t (C)-1,3-bis(phenylmethyl)imidazol-2-ylidene)Ni(CO)3] (970M2472). Complexes of composition [Ni(CO)2L2] with imidazol-2-ylidenes are also known (93JOM(459)177). Another species to be mentioned in this respect is bis(l,3-dimesitylimidazol-2-ylidene)nickel(0) (94JA4391). 1,3-Dicyclohexylimidazol-2-yUdene substitutes triphenylphosphine or THF from [NiX LJ (X = Cl, Br L PPhj, THF) to yield the stable nickel(II) complexes 69 (X = C1, Br R = Cy) (97OM2209). Another preparation of nickel(II) derivatives is the interaction of... 

The l-chloro-2,2-dibromocyclopropanes 164 similarly undergo the nickel-carbonyl-induced ring-opening carbonylation with an amine or an alcohol to give the / ,y-unsaturated carboxylic acid derivatives 165 and the dicarboxylic acid ones 166 [84]. The mechanism described above appears to be operating this is supported by the four-component condensation to 167. (Scheme 61 and 62)... 

A nickel(II) species is also though to be an intermediate in the carbonyla-tion reaction of iodobenzene with (V-methylbenzaldimine and nickel carbonyl. Two addition modes of an ensuing aroylnickel(II) complex to the C=N double bond can be envisaged as routes to l-methyl-2-phenylindol-3-one and an ethylenediamine derivative (Scheme 47).7 5 The scope of this simple indole synthesis has not been assessed. 

The course of the reaction of phenacyl bromides (39) with nickel carbonyl is markedly dependent on the solvent employed in tetrahydrofuran the products are 1,2-dibenzoylethanes (cf. 40) but in dimethylformamide, 2,5-diarylfurans (41) are obtained in moderate to excellent yield (Scheme 53).90 It is possible that the furan derivatives (41) arise via intermediate fi,y-epoxyketones which can be isolated as products from a number of a-bromo-ketone substrates [cf. 39 and Section II].28... 

The formation of l,3,4-triarylpyrroline-2,5-diones from the reaction of diphenylcyclopropenone and N-sulfinylarylamines with nickel carbonyl has been described earlier (see Scheme 36 in Section IV,A,2).64 In contrast with this result, 2,4,5-triphenyl-3-isothiazolone 1-oxide is produced in this type of process using iron pentacarbonyl, and the analogous cyclohexyl derivative is formed in a nickel carbonyl-mediated reaction (Scheme 115).64 It is probable that metallocyclic species (cf. 93) are intermediates in these transformations. 

A 1,3-oxathiolane derivative (100) is formed when 2-mercaptoethanol is carbonylated by nickel carbonyl in pyridine (Scheme 118).181 It is probable that the mechanism involves carbonyl insertion into the Ni—S bond of intermediate thiolatonickel complexes and it is significant that compounds in this category (cf. 101,102) can be transformed into the cyclic thiocarbonate by treatment with carbon monoxide (Scheme 118).181... 

As, for the most part, the corresponding ester derivatives are a more important synthetic target, recent literature has demonstrated methods to prepare the esters directly. Examples include the use of nickel carbonyl in a methanol/dimethylformamide solvent system(37) the direct conversion of benzyl alcohol to methylphenyl-acetate using cobalt carbonyl(38) and a reaction system which utilizes an ammonium salt bound to an organic polymer(39). 

The ability of nickel complexes, e.g., nickel carbonyl and its phosphine derivatives, to catalyze polymerization and other reactions of olefins and acetylenes has been studied extensively (46, 53), particularly by Reppe. 

Attempts to purify the material further met with little success because of its extreme sensitivity toward oxygen. Recrystallization from ether, for instance, in a modified Schlenk tube (25), with exclusion of air, invariably led to an off-colored product. An attempt to sublime the product in a high vacuum resulted in complete decomposition. Analysis even on the crude product, however, confirmed its identity as a disubstituted derivative of nickel carbonyl. 

Bromo-ll//-pyrido[2,l-b]quinazolin-ll-one and its 8-methyl and 8-isopropyl derivatives (127, R = Br, R1 = H, Me, iPr) were treated with carbon monoxide and nickel carbonyl in wet dimethylformamide in the presence of calcium hydroxyde to yield 2-carboxylic acid derivatives (127, R = COOH, R1 = H, Me, iPr). 2-Bromo-8-isopropyl-ll//-pyrido[2,l-b]-quinazolin-ll-one (127, R = Br, R1 = iPr) was reacted with copper(I) cyanide in iV-methyl-2-pyrrolidone at 180°C for 10 h, then with ferric chloride hexahydrate in diluted hydrochloric acid at 90°C for 30 min to give the 2-cyano derivative (127, R = CN, R1 = iPr) (85CP1189509). 

IR spectroscopy has been used to characterize the CO group bound to nickel(O). The v(CO) stretching frequency shifts to lower frequency upon coordination as a consequence of Jt back-bonding interactions it occurs at about 1900-1980 cm-1 in bis(carbonyl) derivatives and... 

A number of new methods for the preparation of cyclopropanols from carbonyl derivatives via 1,3-bond formation between the carbonyl and carbons have been developed. 7>ons-2-alkylcyclopropanols are stereoselectively produced from 2- or 3-substituted acrolein upon exposure to chromium(II) chloride in the presence of a catalytic amount of nickel chloride in DMF (equation 56)73. 2,3-Disubstituted acroleins are, in contrast, inert to the chromium reagent. Treatment of / -stannyl carbonyls with titanium(IV) chloride affords cyclopropanols in good yields when the substrates are ketones not bearing j -alkyl... 

In 1980 we published a survey (1) of our major results in this area as of late 1979. These results include extensive work on binuclear CF N PF complexes of cobalt (2,3,4,5) and nickel (6). This paper summarizes our more recent results in this area with particular emphasis on binuclear complexes of chromium, molybdenum, and tungsten as well as some new results on iron carbonyl derivatives. 

A series of complexes of 2-carbonyl derivatives of 3-hydroxybenzo[b]thiophene 679, its imines 680 (R/ = Ph) [250] and hydrazones 680 (R = NR2R3) [251], as well as pyperidine adduct of nickel complex 681 [252], have been isolated in methanol-ethanol mixture ... 

Aromatic halides are reported to give only carbonylated products with nickel tetracarbonyl. In contrast, pentafluorophenyl iodide in DMF gives decafluorobiphenyl in 70% yield (27). From the other products obtained (pentafluorobenzene, decafluorobenzophenone) it has been suggested that a radical mechanism is involved. The reactions of benzyl halides with nickel carbonyl in various solvents have been reported (28). The main reaction involves carbonylation, as discussed in Section III. Using benzene as solvent, a 33% yield of bibenzyl may be obtained. Here again a mechanism involving a 7r-allylnickel derivative should perhaps be considered, particularly since such a system is known to exist in (XVI) (29). 

We have already mentioned that it is the cis isomer of the 2,5-hexadienoyl halide which in the presence of nickel carbonyl cyclizes to give a cyclo-pentene derivative. The trans form reacts with acetylene to give (XXXV)... 

Finally, we should mention that, in the light of these results, which established the first contact points between the chemistry of the carbonyl derivatives of nickel and platinum, some analogous palladium derivatives could be expected. Until now, however, all attempts to prepare them have failed giving only palladium metal under a variety of conditions 95). 

In addition to its importance in alloys (for example, alnico, vicalloy, and stellite), cobalt is of use as a catalyst in the Fisher-Tropsch process in which carbon monoxide is hydrogenated to a mixture of hydrocarbons. It appears likely here that one or more carbonyl derivatives of cobalt act as intermediates. Nickel is of importance in a number of alloys Monel metal, alnico, stainless steel, etc.). In a very finely divided state Raney nickel), it is of use to the organic chemist in hydrogenation reactions, for it will absorb large quantities of hydrogen gas with probable breakage of the molecules to atoms (p. 27). 

When inhaled even in small quantities the vapour of nickel carbonyl is very poisonous,1 being decomposed in the lungs to carbon monoxide and a nickel derivative—possibly the basic carbonate. 

Significance of the constitutional nature of nickel carbonyls and their w-complex derivatives in poisonings and cancerogenesis New reagent—nickel tetracarbonyl... 

Acrylic Acid, Acrylates, and Acrylonitrile. Acrylic acid [79-10-7], C3H402, and acrylates were once prepared by reaction of acetylene and carbon monoxide with water or an alcohol, using nickel carbonyl as catalyst. I11 recent years tliis process has been completely superseded in the United States by newer processes involving oxidation of propylene (2). I11 western Europe, however, acetylene is still important in acrylate manufacture (see Acrylic acid and derivatives Acrylic ester polymers). 

The general mechanistic picture presented above applies to a number of synthetically useful systems including the first to be discovered, in which trimerization of acetylene to benzene, and propargyl alcohol to a 1 1 mixture of 1,2,4- and 1,3,5-trisubstituted benzene derivatives was catalyzed by (Ph3P)2Ni(CO)2. Phosphine nickel carbonyls are usually much more highly regioselective for 1,2,4-... 

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