14250-73-8

A process for producing a mixture comprising tertiary isononanoic acids proceeding from 2-ethylhexanol is characterized in that 2-ethylhexanol is (a) reacted at a temperature of 0° C. to 40° C. with a mixture of concentrated formic acid and a concentrated Br?nsted acid, wherein 2 to 10 mol of formic acid are used per mole of 2-ethylhexanol and the concentrated Br?nsted acid is used in an amount that corresponds to 6 to 90 mol of protons per mole of 2-ethylhexanol. The resulting reaction mixture from step (a) is subsequently (b) brought into contact with water, and the mixture comprising tertiary isononanoic acids formed according to step b) is removed.

A palladium-catalyzed arylation of unactivated γ-methylene C(sp3)-H and remote δ-C-H bonds by using an oxazoline-carboxylate directing group has been developed. Arylation occurs with a broad substrate scope and high tolerance of functional groups (i.e., halogen, nitro, cyano, ether, trifluoromethyl, amine, and ester). The oxazoline-type auxiliary can be removed under acidic conditions.

The direct alkylation of unactivated sp3 C-H bonds of aliphatic amides was achieved via nickel catalysis with the assist of a bidentate directing group. The reaction favors the C-H bonds of methyl groups over the methylene C-H bonds and tolerates various functional groups. Moreover, this reaction shows a predominant preference for sp3 C-H bonds of methyl groups via a five-membered ring intermediate over the sp2 C-H bonds of arenes in the cyclometalation step.

The intramolecular dehydrogenative amidation of aliphatic amides, directed by a bidentate ligand, was developed using a copper-catalyzed sp3 C-H bond functionalization process. The reaction favors predominantly the C-H bonds of β-methyl groups over the unactivated methylene C-H bonds. Moreover, a preference for activating sp3 C-H bonds of β-methyl groups, via a five-membered ring intermediate, over the aromatic sp2 C-H bonds was also observed in the cyclometalation step. Additionally, sp3 C-H bonds of unactivated secondary sp3 C-H bonds could be functionalized by favoring the ring carbon atoms over the linear carbon atoms. Getting ahead on tams: The intramolecular dehydrogenative amidation of aliphatic amides, directed by a bidentate ligand, was developed using a copper-catalyzed sp 3 C-H bond functionalization process to deliver β-lactams. The reaction favors the C-H bonds of β-methyl groups over the unactivated methylene C-H bonds, as well as aromatic C(sp2)-H bonds and unactivated secondary C(sp3)-H bonds of rings.

-

-

A new palladium catalyst was found to exhibit high catalytic activity for carbonylation of olefins and alcohols. cyclo-Bis(μ-carbonyl)dipalladium(I) cation (1) with bridging CO ligands is formed by reductive carbonylation of palladium sulfate, PdSO4, in concentrated H2SO4. When an olefin or alcohol is added, complex 1 changes to a new complex (2) with terminal CO ligands, and tertiary carboxylic acids are obtained in high yields at room temperature and atmospheric pressure of CO. IR and 13C NMR studies suggest that complex 2 may be tentatively formulated to be [Pd2(CO)2]2+, in which the terminal CO ligands are chemically equivalent. Complex 1 is a catalyst precursor, and complex 2 functions as an active species for the carbonylation of olefins and alcohols. The catalytic behavior of the palladium carbonyl catalyst supports the recently proposed reaction mechanism involving an olefin-metal-CO complex as an intermediate for the catalytic carbonylation of olefins and alcohols in strongly acidic solution.

A new gold catalyst, [Au(CO)n]+ (n = 1, 2), was synthesized by using a facile method from commercial gold(III) oxide, Au2O3, in concentrated H2SO4, which exhibits high catalytic activity for carbonylation of olefins. The gold monocarbonyl [Au(CO)]+ (1) and dicarbonyl [Au(CO)2]+ (2) cations coexist in H2SO4 solution, the former of which is much more stable than the latter. Both of the carbonyls show IR spectra of vCO (2194, 2208 cm-1) higher than that of free CO (2143 cm-1), indicating nonclassical (σ-only) gold-CO bonding. The gold carbonyl complexes coexisting in the concd H2SO4 solution exhibit a single resonance in the 13C NMR spectrum at 171 ppm at ambient temperature and pressure, reflecting rapid CO exchange between 1 (164 ppm) and 2 (175 ppm). The nonclassical gold(I) carbonyl solution worked as an excellent catalyst, with which olefins reacted with CO to give tert-carboxylic acids in good yields at room temperature and atmospheric pressure. The gold(I) dicarbonyl cation 2 was found to function as an active species for the carbonylation. An olefin-gold(I)-carbonyl complex was proposed as a possible intermediate in the metal carbonyl-catalyzed carbonylation in the strongly acidic medium.

Organocopper reagents, such as diorganocuprates, organocopper-tributylphosphine, and Grignard reagents in the presence of a copper (I) salt, reacted with β-propiolactones by regioselective β-carbon-oxygen fission to give 3-substituted propionic acids.Among these three kinds of organocopper reagents, diorganocuprate, especially halomagnesium cuprate gave the highest yields of the acids, which was remarkably observed in the ring-opening of sterically hindered β-propiolactones such as β-methyl- and α,β-dimethyl-β-propiolactones and also in the reactions using the organocopper reagents with vinyl and allyl substituents.The ring-opening of β-propiolactone was confirmed to proceed by SN2 pathway with predominant inversion of configuration of the β-carbon by using the reaction of cis-α,β-dimethyl-β-propiolactone with di-tert-butylcuprate to afford syn-2,3,4,4-tetramethylpentanoic acid.

The selective carboxylation of acyclic tert-aliphatic alcohols was successfully performed to produce the corresponding acyclic tert-aliphatic carboxylic acids in significantly high yields using concentrated sufuric acid supersaturated with carbon monoxide.

-

Grignard reagents react with β-propiolactones in the presence of a copper(I) catalyst to give β-substituted propionic acids in high yields.

Various organocuprates react with β-propiolactones to give β-substituted propionic acids in high yields.