Joseph R. Zoeller

A fundamental investigation of the ruthenium-catalyzed homologation of methyl esters with synthesis gas

Abstract The homologation of methyl esters with synthesis gas in the presence of iodine-promoted ruthenium catalysts has been examined. This investigation, which uses a gas-purged liquid-sampling autoclave, shows that there are four major reactions occurring simultaneously. These are homologation of the methyl ester to form an ethyl ester, carbonylation of the methyl ester to generate acetic acid, reduction of the acyl moiety, and hydrogenolysis of the methyl ester to yield methane. When LiI was used as the iodine promoter at an I/Ru ratio of 15/1, the predominant pathways was homologation. When methyl iodide was used as the promoter in place of LiI, a selectivity change resulted. The predominant pathway with methyl iodide was acyl reduction. The relative contribution of each pathway was affected by the partial pressures of carbon monoxide and hydrogen, and by the level of iodine present. A deuterium-labeling experiment was also performed and established the integrity of the processes described above and excluded the hydrogenation of carbon monoxide to methanol as a potential pathway to products.

Sequential acetalization-pyrolysis of α-acetyl benzalacetones. A method for the generation of 6-substituted 2-acetonaphthones

Abstract 6-Substituted 2-acetonaphthones can be generated from para substituted benzaldehydes and acetylacetone (2,4-pentanedione) in three reactions consisting of condensing the benzaldehyde with acetylacetone, acetalizing the resultant 3-benzylidene 2,4-pentanedione (α-acetyl benzalacetones), with trimethyl orthoformate, pyrolyzing the acetal either in the vapor phase at 475°C or by heating in a high boiling solvent, such as 1-methylnaphthalene.

An investigation of the ruthenium-catalyzed homologation of acetic acid with synthesis gas

Abstract Liquid sampling procedures for high-pressure reactions indicate that the ruthenium-catalyzed homologation of acetic acid proceeds through a series of consecutive reactions. The process is characterized by an initial rapid generation of ethanol and ethyl acetate (obtained via hydrogenation and subsequent esterification) followed by the subsequent generation of propionic acid (obtained via carbonylation). Higher ester and acid homologs were also subsequently detected. A gas chromatographic-mass spectroscopic (GC-MS) examination of the product mixture revealed the presence of a homologous series of alkyl iodides which are possible intermediates in the carbonylation of esters to acids. These results and observations by previous workers are explained in the context of other work on ruthenium-catalyzed homologations of organic oxygenates.