Production of carboxylic anhydrides from methyl carboxylates using rhodium complex catalysts.

摘要

@ 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 (=0) oxygen atom attached to a phosphorus atom or a carbon atom to form a Z group and the
<Chemistry id="chema01" num="0001"><Image id="ia01" he="13" wi="24" file="IMGA0001.TIF" imgContent="chem" imgFormat="TIFF" inline="no" /></Chemistry>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
<Chemistry id="chema02" num="0002"><Image id="ia02" he="24" wi="111" file="IMGA0002.TIF" imgContent="chem" imgFormat="TIFF" inline="no" /></Chemistry>
or
<Chemistry id="chema03" num="0003"><Image id="ia03" he="27" wi="136" file="IMGA0003.TIF" imgContent="chem" imgFormat="TIFF" inline="no" /></Chemistry><!-- EPO <DP n="2"> -->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.