Carboxylic acids by carboxylation with formic acid

Carboxylic acids by carboxylation with formic acid, 46, 74 Catalyst, palladium (Lindlar), 46, 89 Chloramine, 46, 18... 

Adamantane, prepared according to Schleyer and supplied by Aldrich Chemical Co., can be converted into the 1 -carboxylic acid by carboxylation with formic acid, (-butanol, and 96% sulfuric acid,2 orfrom 1-bromoadamantane, formic acid, and 96% sulfuric acid.3... 

Carboxylic acids by carboxylation with formic acid, 46, 74... 

These reactions are most important for the preparation of acyl fluorides. " Acyl chlorides and anhydrides can be converted to acyl fluorides by treatment with polyhydrogen fluoride-pyridine solution" or with liquid HF at — 10°C. Formyl fluoride, which is a stable compound, was prepared by the latter procedure from the mixed anhydride of formic and acetic acids. Acyl fluorides can also be obtained by reaction of acyl chlorides with KF in acetic acid or with DAST. Carboxylic esters and anhydrides can be converted to acyl halides other than fluorides by the inorganic acid halides mentioned in 10-77, as well as with PhsPXa (X = Cl or but this is seldom done. Halide exchange can be carried out in a... 

Males et al. [103] used aqueous mobile phase with formic acid for the separation of flavonoids and phenolic acids in the extract of Sambuci flos. In a cited paper, authors listed ten mobile phases with addition of acids used by other investigators for chromatography of polyphenolic material. For micropreparative separation and isolation of antraquinone derivatives (aloine and aloeemodine) from the hardened sap of aloe (Liliaceae family), Wawrzynowicz et al. used 0.5-mm silica precoated plates and isopropanol-methanol-acetic acid as the mobile phase [104]. The addition of small amounts of acid to the mobile phase suppressed the dissociation of acidic groups (phenolic, carboxylic) and thus prevented band diffusions. 

Infra-red, microwave, and X-ray photoelectron spectroscopy Infra-red and ultra-violet spectroscopy has been widely used for investigating the structure of intermolecularly hydrogen-bonded complexes in the solid state (Novak, 1974) and in solution (Zundel, 1976, 1978 Clements et al., 1971a,b,c Pawlak et al., 1984). By analysing the infra-red spectra of equimolar liquid mixtures of amines with formic or acetic acid, the relative importance of structures [10] and [11] was estimated (Lindemann and Zundel, 1977). It was proposed that [10] and [11] make equal contributions to the observed structure of the complex when the p -value of the carboxylic acid is approximately two units lower than that of the protonated amine. 

The hydrolysis of diethyl N-(3-alkoxycarbonyl-2-thienyl)aminomethy-lenemalonates (1439, R = Me, Et) by potassium hydroxide in ethanol yielded diethyl Af-(3-carboxy-2-thienyl)aminomethylenemalonates (1439, R = H) [75GEP2435025, 75JAP(K)77393]. The treatment of the /erf-butyl esters 1439, R = rBu, R1 = R2 = H, Me, (CH2)4] with formic acid or trifluoroacetic acid at room temperature also afforded the carboxylic acid derivatives [1439, R = H, R = R2 = H, Me, (CH2)4] [75JAP(K)77394]. 

Adamantanecarboxylic acids with a carboxylic group at a bridgehead position, e.g. adaman-tane-1-carboxylic acid (8),111 react with sulfur tetrafluoride in the conventional way giving high yields of the corresponding trifluoromethyl-substituted adamantanes. l-(Trifluoromethyl)-adamantane (9) can also be formed in one step from adamantane by treatment with a mixture of sulfur tetrafluoride, hydrogen fluoride and formic acid the latter serves as a source of carbon monoxide. The reaction is believed to proceed via carbonylation of an intermediate carbocat-... 

The methyl ester has also been obtained by esterification of cyclopentanecarboxylic acid.8 The acid, in turn, has been prepared by the Favorskii rearrangement,6 7 9-11 by the reaction of cyclopentyl Grignard reagent with carbon dioxide,12 by the carbonylation of cyclopentyl alcohol with nickel carbonyl13 or with formic acid in the presence of sulfuric acid,14 and by the hydrogenation of cyclopentene-1-carboxylic acid prepared from ethyl cyclopentanone-2-carboxylate 15 or from cyclopentanone cyanohydrin.16... 

Esters of allylic alcohols with resin-bound carboxylic acids can be converted into allyl palladium complexes, which react with carbon nucleophiles and with hydride sources to yield the formally reduced allyl derivatives (Entries 3 and 4, Table 3.47). Alkyl sulfonates have been reduced to alkanes with NaBH4 (Entry 5, Table 3.47). Aryl sulfonates (Entry 6, Table 3.47) and aryl perfluoroalkylsulfonates [814] can be reduced to alkanes by treatment with catalytic amounts of Pd(II) and formic acid as a hydride source. 

As shown in Scheme 5.1, formic acid behaves differently to other carboxylic acids. Expected octadienyl formate is not formed. The reaction with formic acid in the presence of EtjN affords 1,7-octadiene (140) [62 64], The first step is the protonation of bis-Ji-allylpalladium 68 with formic acid to generate 167. Formic acid is a hydride source, ft is known that the Pd hydride, formed by the decarboxylation of palladium formate, attacks the substituted side of 7i-allylpalladium as shown by 167 to form the terminal alkene 140 [65], The regioselective attack of Pd—H at the more substituted side of 7r-allyl systems is covered in Section 4.3.7. 

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