Formic acid catalysts

In the presence of diethylamine-formic acid catalyst, l-nitro-2-alkanols (416) are added to the double bond of acrylaldehyde, forming, in 40-80% yield,... 

H2O and formic acid catalyst (18-hour reaction time). The reaction is... 

Formic acid is a comparatively strong acid and acta as its own catalyst. 

By passing a mixture of carbon monoxide and hydrogen chloride into the aromatic hydrocarbon in the presence of a mixture of cuprous chloride and aluminium chloride which acts as a catalyst (Gattermann - Koch reaction). The mixture of gases probably reacts as the equivalent of the unisolated acid chloride of formic acid (formyl chloride) ... 

Formate is an excellent hydride source for the hydrogenolysis of aryl halides[682]. Ammonium or triethylammonium formate[683] and sodium formate are mostly used[684,685]. Dechlorination of the chloroarene 806 is carried out with ammonium formate using Pd charcoal as a catalyst[686]. By the treatment of 2,4,6-trichloroamline with formate, the chlorine atom at the /iiara-position is preferentially removed[687]. The dehalogenation of 2,4-diha-loestrogene is achieved with formic acid, KI, and ascorbic acid[688]. 

The enone 807 is converted into the dienol triflatc 808 and then the conjugated diene 809 by the hydrogenolysis with tributylammonium for-mate[689,690]. Naphthol can be converted into naphthalene by the hydrogenolysis of its triflate 810[691-693] or sulfonates using dppp or dppf as a ligand[694]. Aryl tetrazoyl ether 811 is cleaved with formic acid using Pd on carbon as a catalyst[695]. 

Formic acid is a good reducing agent in the presence of Pd on carbon as a catalyst. Aromatic nitro compounds are reduced to aniline with formic acid[100]. Selective reduction of one nitro group in 2,4-dinitrotoluene (112) with triethylammonium formate is possible[101]. o-Nitroacetophenone (113) is first reduced to o-aminoacetophenone, then to o-ethylaniline when an excess of formate is used[102]. Ammonium and potassium formate are also used for the reduction of aliphatic and aromatic nitro compounds. Pd on carbon is a good catalyst[103,104]. NaBH4 is also used for the Pd-catalyzed reduction of nitro compounds 105]. However, the ,/)-unsaturated nitroalkene 114 is partially reduced to the oxime 115 with ammonium formate[106]... 

Formaldehyde polymerizes even without added catalyst, but it is possible that traces of formic acid act as adventitious catalysts in this system. 

Butane-Naphtha Catalytic Liquid-Phase Oxidation. Direct Hquid-phase oxidation ofbutane and/or naphtha [8030-30-6] was once the most favored worldwide route to acetic acid because of the low cost of these hydrocarbons. Butane [106-97-8] in the presence of metallic ions, eg, cobalt, chromium, or manganese, undergoes simple air oxidation in acetic acid solvent (48). The peroxidic intermediates are decomposed by high temperature, by mechanical agitation, and by action of the metallic catalysts, to form acetic acid and a comparatively small suite of other compounds (49). Ethyl acetate and butanone are produced, and the process can be altered to provide larger quantities of these valuable materials. Ethanol is thought to be an important intermediate (50) acetone forms through a minor pathway from isobutane present in the hydrocarbon feed. Formic acid, propionic acid, and minor quantities of butyric acid are also formed. 

Formaldehyde is readily reduced to methanol by hydrogen over many metal and metal oxide catalysts. It is oxidized to formic acid or carbon dioxide and water. The Cannizzaro reaction gives formic acid and methanol. Similarly, a vapor-phase Tischenko reaction is catalyzed by copper (34) and boric acid (38) to produce methyl formate ... 

Formic acid forms esters with primary, secondary, and tertiary alcohols. The high acidity of formic acid makes use of the usual mineral acid catalysts unnecessary in simple esterifications (17). Formic acid reacts with most amines to form formylamino compounds. With certain diamines imida2ole formation occurs, a reaction that has synthetic utiHty (18) ... 

Formic acid can decompose either by dehydration, HCOOH — H2O + CO (AG° = —30.1 kJ/mol AH° = 10.5 kJ/mol) or by dehydrogenation, HCOOH H2 + CO2 (AG° = —58.6 kJ/mol AH° = —31.0 kJ/mol). The kinetics of these reactions have been extensively studied (19). In the gas phase metallic catalysts favor dehydrogenation, whereas oxide catalysts favor dehydration. Dehydration is the predominant mode of decomposition ia the Hquid phase, and is cataly2ed by strong acids. The mechanism is beheved to be as follows (19) ... 

The carbonylation of methanol [67-56-1] to methyl formate ia the presence of basic catalysts has been practiced iadustriaHy for many years. Ia older processes for formic acid utili2ing this reactioa, the methyl formate [107-31-3] reacts with ammonia to give formamide [75-12-7] which is hydroly2ed to formic acid ia the preseace of sulfuric acid ... 

The carboaylatioa of methanol to give formic acid is carried out ia the Hquid phase with the aid of a basic catalyst such as sodium methoxide. It is important to minimi2e the presence of water and carbon dioxide ia the startiag materials, as these cause deactivatioa of the catalyst. The reactioa is an equHibrium, and elevated pressures are necessary to give good conversions. Typical reaction conditions appear to be 80°C, 4.5 MPa (44 atm) pressure and 2.5% w/w of catalyst. Under these conditions the methanol conversion is around 30% (25). 

Aldehyde Synthesis. Formylation would be expected to take place when formyl chloride or formic anhydride reacts with an aromatic compound ia the presence of aluminum chloride or other Friedel-Crafts catalysts. However, the acid chloride and anhydride of formic acid are both too unstable to be of preparative iaterest. 

Olefins are carbonylated in concentrated sulfuric acid at moderate temperatures (0—40°C) and low pressures with formic acid, which serves as the source of carbon monoxide (Koch-Haaf reaction) (187). Liquid hydrogen fluoride, preferably in the presence of boron trifluoride, is an equally good catalyst and solvent system (see Carboxylic acids). 

Ion implantation has also been used for the creation of novel catalyticaHy active materials. Ruthenium oxide is used as an electrode for chlorine production because of its superior corrosion resistance. Platinum was implanted in mthenium oxide and the performance of the catalyst tested with respect to the oxidation of formic acid and methanol (fuel ceU reactions) (131). The implantation of platinum produced of which a catalyticaHy active electrode, the performance of which is superior to both pure and smooth platinum. It also has good long-term stabiHty. The most interesting finding, however, is the complete inactivity of the electrode for the methanol oxidation. 

Oxidation. Maleic and fumaric acids are oxidized in aqueous solution by ozone [10028-15-6] (qv) (85). Products of the reaction include glyoxyhc acid [298-12-4], oxalic acid [144-62-7], and formic acid [64-18-6], Catalytic oxidation of aqueous maleic acid occurs with hydrogen peroxide [7722-84-1] in the presence of sodium tungstate(VI) [13472-45-2] (86) and sodium molybdate(VI) [7631-95-0] (87). Both catalyst systems avoid formation of tartaric acid [133-37-9] and produce i j -epoxysuccinic acid [16533-72-5] at pH values above 5. The reaction of maleic anhydride and hydrogen peroxide in an inert solvent (methylene chloride [75-09-2]) gives permaleic acid [4565-24-6], HOOC—CH=CH—CO H (88) which is useful in Baeyer-ViUiger reactions. Both maleate and fumarate [142-42-7] are hydroxylated to tartaric acid using an osmium tetroxide [20816-12-0]/io 2LX.e [15454-31 -6] catalyst system (89). 

Propionic acid is accessible through the Hquid-phase carbonylation of ethylene over a nickel carbonyl catalyst (104), or via ethylene and formic acid over an iridium catalyst (105). Condensation of propionic acid with formaldehyde over a supported cesium catalyst gives MAA directiy with conversions of 30—40% and selectivities of 80—90% (106,107). Catalyst lifetime can be extended by adding low levels (several ppm) of cesium to the feed stream (108). 

Nylon-11. Nylon-11 [25035-04-5] made by the polycondensation of 11-aminoundecanoic acid [2432-99-7] was first prepared by Carothers in 1935 but was first produced commercially in 1955 in France under the trade name Kilsan (167) Kilsan is a registered trademark of Elf Atochem Company. The polymer is prepared in a continuous process using phosphoric or hypophosphoric acid as a catalyst under inert atmosphere at ambient pressure. The total extractable content is low (0.5%) compared to nylon-6 (168). The polymer is hydrophobic, with a low melt point (T = 190° C), and has excellent electrical insulating properties. The effect of formic acid on the swelling behavior of nylon-11 has been studied (169), and such a treatment is claimed to produce a hard elastic fiber (170). 

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