Sodium cobalt carbonyl

Additional support for the carbon monoxide-alkoxycobalt insertion reaction is found in the reaction of tert-butyl hypochlorite with sodium cobalt carbonyl. This reaction, if carried out at — 80°C. in ether solution under nitrogen or carbon monoxide, leads to about a 10% yield of /er/-butoxycarbonylcobalt tetracarbonyl which has been isolated as the monotriphenylphosphine derivative. The major product seems to be cobalt octacarbonyl, possibly formed by decomposition of an intermediate JerJ-butoxycobalt tetracarbonyl (34). This reaction appears to be a true insertion reaction although a direct attack of a coordinated carbonyl group upon oxygen cannot be ruled out. 

Heck demonstrated Eq. (89) for a number of acylcobalt carbonyls, preparing them from the corresponding alkyl halide and sodium cobalt carbonylate. In the presence of bases, cobalt hydrocarbonyl regenerated cobalt carbonylate ion and a catalytic reaction resulted at atmospheric pressure and at temperatures from 0° to 100° C. Thus the following reaction was reported in 56% yield at 50° C ... 

The base (B) used was dicyclohexylethylamine. At the higher temperatures the isomeric products that one would expect from an isomerization of the acylcobalt carbonyls were formed (see Section II, A). Amines were also used in place of alcohols to give amides. Thus benzyl chloride reacted with carbon monoxide and aniline in tetrahydrofuran solution at 35° C in the presence of sodium cobalt carbonylate catalyst to give a 47% yield of phenylacetanilide. 

A catalytic carboxyalkylation can also occur if the acylcobalt carbonyl is formed from an epoxide and sodium cobalt carbonylate ion. This reaction is discussed in Section II, D,l,a. 

Sodium cobalt carbonylate, Na Co(CO)4". Colorless powder insoluble in water. It is prepared from dicobalt octacarbonyl and sodium amalgam in ether solution under nitrogen. If a solution in another solvent is required the ether is evaporated in vacuum and the new solvent is added with exclusion of air. 

Heck and Breslow found that alkyl halides, sulfates, and sulfonates undergo carboalkoxylation in the presence of carbon monoxide, an alcohol, a base, and a catalytic amount of sodium cobalt carbonylate, as illustrated for the reaction of 1-iodooctane in methanol with the strongly basic hindered amine dicyclohexylethyl-amine as base. Use of an unhindered amine leads to formation of the amide. 

Carboalkoxylation Ethyl diethoxyphoiphlnyl formale. Sodium cobalt carbonylate. Carbbne, lUHirruTED, oineration ( lo laaomethane (dec.)- CHCl. Chloroform... 

Sodium cobalt carbonylate carbon monoxide Ethylene derivatives from 1,2-acoxyhalides... 

A mixture of 3-hexyne, chloracetonitrile, sodium cobalt carbonylate, and dicyclohexylethylamine in ether allowed to stand overnight in a flask filled with CO at 25° and connected to a gas buret 2,3-dielhyl-5-cyano-2,4-penta-dieno-4-lactone. Y 62%. F. e. s. R. F. Heck, Am. Soc. 86, 2819 (1964). 

Sodium cobalt carbonylate j -Hydroxycarboxylic acid esters from oxido compounds Synthesis with addition of 1 C-atom... 

Activated mercaptans undergo desulfurization to hydrocarbons using cobalt carbonyl or triiron dodecacarbonyl as the metal complex, and basic phase transfer conditions (5 ). Acidic phase transfer catalysis has been little investigated, the first example in organometallic chemistry being reported in 1983 (reduction of diarylethylenes)( ). When acidic phase transfer conditions (sodium 4-dodecylcenzenesulfo-nate as the phase transfer catalyst) were used for the desulfurization of mercaptans [Fe3(CO)] 2 the metal complex],... 

As the supported glycol catalysts worked better in promoting reactions in a single solvent system, we explored the direct carbonylation of benzyl halides using an alcohol solvent, base, and cobalt carbonyl. Our initial experiments concentrated on the reaction of benzyl bromide at room temperature and one atmosphere carbon monoxide. We chose sodium hydroxide as the base, methanol as the solvent, and looked at the product distribution. We were interested in the selectivity to ester and the reactivity of this system. The results are given in Table III. 

The results from our work on the reaction of propylene oxide with cobalt carbonyl and base in methanol are given in Table VIII. Several base/metal oxide combinations were evaluated under mild reaction conditions. The difference in activity between the bases was not as pronounced as that observed in the reaction with benzyl halides with the exception of potassium methoxide which, when used alone, gave exclusively the hydroxy ether resulting from methoxide addition to the epoxide ring. However, the activity of sodium... 

Cyclododecene may be prepared from 1,5,9-cyclododecatriene by the catalytic reduction with Raney nickel and hydrogen diluted with nitrogen, with nickel sulfide on alumina, with cobalt, iron, or nickel in the presence of thiophene, with palladium on charcoal, with palladimn chloride in the presence of water, with palladium on barium sulfate, with cobalt acetate in the presence of cobalt carbonyl, and with cobalt carbonyl and tri- -butyl phosphine. It may also be obtained from the triene by reduction with lithium and ethylamine, by disproportionation, - by epoxidation followed by isomerization to a ketone and WoliT-Kishner reduction, and from cyclododecanone by the reaction of its hydrazone with sodium hydride. ... 

Some 2,3-unsaturated sugars have also been prepared by the reaction of 2-iodinated carbohydrates with sodium cobalt tetra-carbonyl and carbon monoxide.188 Methyl 3,4,6-tri-0-acetyl-2-deoxy-2-iodo-/3-D-glucopyranoside (149) in ether reacts at room temperature to give, in high yield, methyl 4,6-di-0-acetyl-2,3-dideoxy-/3-D-eri/thro-hex-2-enopyranoside (150). Under the same reaction conditions,... 

One of the complexes formed in the reaction of diphenylacetylene and iron dodecacarbonyl is a red, crystalline compound of the composition [Fe2(CO)6(PhC2Ph)], which, on reduction with sodium in liquid ammonia, gives dibenzyl (117). By analogy with the cobalt carbonyl complex, structure (XXXV M = Fe) is proposed, in which the 7r-elcctrons of the triple... 

A series of cobalt carbonyl complexes of polyphosphazenes have been prepared via arene coordination sites. Examples are shown as 3.65 and 3.66.112 These are synthesized via the reactions of (NPC12) with the sodium salt of the appropriate metal-arene terminated alcohol. Mixed-substituent polymers with trifluoroethoxy or phenoxy cosubstituents have also been prepared. 

Heck and Breslow (63) obtained evidence relating to Eq. (52) for the case of cobalt. They reacted a number of alkyl and acyl halides carrying functional groups with sodium cobalt tetracarbonylate under carbon monoxide. Normal acylcobalt carbonyls were readily formed except for the case of chloroacetonitrile, where a cyanomethylcobalt carbonyl was isolated. Apparently an a-nitrile group is sufficiently electronegative to stabilize the alkylcobalt carbonyl against carbonylation. 

It was suggested that such derivatives would have unusual stability like the corresponding 7r-allyl complexes and would be further reduced by hydrocarbonyl rather than undergoing carbonylation. Heck (63) has, however, attempted the preparation of similar derivatives from chloroacetone and phenacyl bromide with sodium cobalt tetracarbonylate, Instead of finding unusually stable complexes he reported an unusual instability. It seems likely that in fact normal alkylcobalt carbonyls are formed, e.g.,... 

A. Rosenthal and J. N. C. Whyte, Reaction of anhydro sugars with sodium cobalt tetra-carbonyl and carbon monoxide, Can. J. Chem., 46 (1968) 2239-2243. 

The foregoing implies that the addition of an electron to cobalt carbonyl (or the dimer) leads to the formation of the cobalt carbonyl anion. If this is indeed the situation, then it should be possible to convert dicobalt octacarbonyl to the anion by an external source of electrons as well as by a homomolecular disproportion. Such a conversion was achieved by shaking a benzene solution of dicobalt octacarbonyl with sodium amalgam ... 

Surprisingly, the 2,3-epoxide ring of pyranoid or furanoid derivatives proved to be highly unreactive toward carbonyl insertion reactions or in rearrangement to ketoses, either when catalyzed by hydrogen cobalt tetracarbonyl or sodium cobalt tetracarbonyl. When moisture was not carefully excluded, preferential hydrolysis of the epoxide ring occurred to afford the diaxial product. 

Uninegative cobalt is found in sodium tetracarbonylcobaltate(—I), NaCo(CO)4, which is a typical salt with the anion [ 0(00)4] This and the corresponding salts of potassium and calcium are related to cobalt carbonyl hydride (p, 303). 

It is reported that the two-phase carbonylation methodology has been used on a pilot plant scale by Montedison [31 ] for the conversion of benzyl chloride to phenylacetic acid for use in perfume constituents and pesticides (eq. (8)). The carbonylation is run in a biphasic medium employing diphenyl ether and aqueous 40 % sodium hydroxide as solvents. The catalyst system consists of a cobalt carbonyl complex and a benzyltrialkylammonium surfactant. The reaction takes place at low temperature and CO pressure, while benzyl chloride is added continuously to the reaction mixture. 

The carbonylation of a benzyl halide in the presence of iron pentacarbonyl to give a phenylacetic acid may serve to exemplify the interaction of a metal carbonyl, carbon monoxide, PT catalyst, aqueous sodium hydroxide, and the substrate [79]. Fe(CO)5 is attacked by QOH at the interphase, and the species formed is extracted into the depths of the oganic phase, where it reacts with CO and benzyl halide (Eqs. 13 and 14). This new anion 3 is the actual catalyst. It reacts with a second benzyl halide to give a non-ionic intermediate 4 (Eq. 15). By insertion of CO and attack of QOH, 4 is decomposed to the reaction product under regeneration of 3 (Eq. 16). Thus, the action of the PT catalyst is twofold. Firstly it transports the metal carbonyl anion. More important seems to be its involvement in the (rate-determining) decomposition step. A basically similar mechanism was proposed for cobalt carbonyl reactions [80], which have been modified somewhat quite recently (see below). 

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