Abstract: A process for the production of organic carboxylic anhydrides by the catalytic reaction of a methyl carboxylate and carbon monoxide in contact with a homogeneous catalyst system of rhodium metal atom, a phosphorus-containing ligand in which there is present at least one oxo (.dbd.O) oxygen atom attached to a phosphorus atom or a carbon atom to form a Z group and the ##STR1## group in said Z group is located at least one carbon atom removed and preferably from 2-4 carbon atoms removed from the phosphorus atom of the molecules represented by the formulas ##STR2## and a halogen source, under mild reaction conditions, wherein R' is aryl, alkaryl, aralkyl or alkyl, and wherein 1 or more of said R' groups can be substituted with a Z group but not more than 3 of said R' groups in the molecule are so substituted; a is an integer from 0-4; b is an integer from 0-3; and Z is P(O)R'R'; --C(O)OR" or C(O)R", wherein R" is R' or --H.

Abstract: A process for the production of an aldehyde at high selectivity and rate by the reaction of an inorganic or organic ester with carbon monoxide or synthesis gas in contact with a catalyst system containing cobalt, rhodium or ruthenium atoms and lithium iodide and, optionally, an organic ligand.

Abstract: A process for the production of an aldehyde at high selectivity and rate by the reaction of an organic ester with carbon monoxide or synthesis gas in contact with a catalyst system containing rhodium atoms and cobalt atoms and lithium iodide or lithium bromide and, optionally, an organic ligand.

Abstract: Saturated aliphatic aldehydes are prepared by contacting diesters of carbonic acid with synthesis gas and a Group VIII compound, preferably a cobalt compound, a halogen, and optionally a Group V trivalent ligand.

Abstract: Saturated aliphatic aldehydes are prepared by contacting acetals or ketals with synthesis gas and a Group VIII compound, preferably a cobalt compound.

Abstract: Process for selective production of acetaldehyde and dimethyl acetal by the reaction of methanol with carbon monoxide in contact with a catalyst containing cobalt atom, halide atom and a mixture of a trivalent phosphorus compound and a trivalent nitrogen compound. The amount of trivalent nitrogen compound in its mixture varies from 5 mole percent to 50 mole percent of such mixture.