Richard W. Wegman

A highly efficient catalyst system for the isomerization of methyl formate to acetic acid

Abstract Rh-LiI is a highly efficient catalyst for the isomerization of methyl formate to acetic acid. At 180°C the methyl formate conversion is ⪢99% and the molar selectivity to acetic acid is ⪢99%. Lil promotes the reaction apparently by cleaving methyl formate and methyl acetate, which is formed during the course of the reaction, to CH3I and the corresponding lithium formate and lithium acetate salts.

Cobalt-catalyzed reductive carbonylation of methyl esters to acetaldehyde and carboxylic acid

Abstract The reaction of methyl esters with synthesis gas and a Co—LiI catalyst results in the formation of anhydrous acetaldehyde and a carboxylic acid in very high yield. At 180 °C and 5000 psig, acetaldehyde is produced from methyl acetate at a rate of 7 M h −1 and >95% selectivity.

Carbonylation of methanol at unusually low temperature and pressure with cis-RhCl(CO)2Ph2P(CH2)2P(O)Ph2

cis-RhCl(CO)2Ph2P(CH2)2P(O) Ph2, the only species observed during catalysis, formed from cis-[graphic omitted])Ph2 and CO, is the sole active species observed during catalytic studies and results in the carbonylation of methanol with catalyst turnover frequencies approaching 400 h–1 at 80 °C and 50 psig CO; the crystal structure of the analogue cis-[graphic omitted])Ph2 is reported.

The role of phosphines and solvents in CoI2-catalyzed reductive carbonylation of methanol

Abstract The role of triphenylphosphine and solvents in the CoI 2 -catalyzed reductive carbonylation of methanol to acetaldehyde has been studied. When utilized within a controlled molar range, triphenylphosphine has little, if any, effect on the acetaldehyde rate and selectivity. It does serve to reduce corrosion to an acceptable level. Acetaldehyde selectivity is markedly improved by use of a solvent. With few exceptions, most solvents readily decompose under reaction conditions.

Vapour phase carbonylation of methanol or dimethyl ether with metal-ion exchanged heteropoly acid catalysts

Metal-ion exchanged heteropoly acids of the general formula M[W12PO40](M = a group VIII metal) supported on SiO2 have been found to be excellent catalysts for the vapour phase carbonylation of methanol or dimethyl ether to methyl acetate at 225 °C and 1 atm total operating pressure.

A novel catalyst for the low pressure, low temperature homologation of methanol

Methanol is homologated to ethanol with high selectivity (80 mol%) at low pressure and temperature (1000 lb in–2; 140 °C) with a novel rhodium–ruthenium–diphosphine–methyl iodide catalyst.

The reaction of methoxy ketals and dimethyl carbonate with synthesis gas

Abstract The reaction of dimethoxy ketals and dimethyl carbonate with synthesis gas results in the formation of acetaldehyde. In the case of methoxy ketals, the reaction is carried out with a cobalt catalyst at 130 °C and 2500 psi. The rate of acetaldehyde formation is 4.0 M h −1 . The reaction of dimethyl carbonate requires a cobalt-iodide catalyst and operating conditions of 180 °C and 4000 psi. In this case, the rate of formation of acetaldehyde approaches 30 M h −1 . Mechanisms are discussed which are consistent with results obtained from high pressure infrared studies and stoichiometric model reactions.

Cobalt-catalysed reductive carbonylation of methyl esters

Acetaldehyde and a carboxylic acid are obtained in high yield via the Col2–Lil-catalysed reaction of a methyl ester with synthesis gas.