Carbonylation ligands and their use in the carbonylation of ethylenically unsaturated compounds

A novel bidentate ligand of general formula (I)

• wherein:
• A and B represent Co or a methylene group wherein by C0 is meant that the group Q1 or Q2 is connected directly to the R group and there is no methylene group and in this case the other group cannot be C0 and must be a methylene group and, therefore, at least one of A and B is a methylene group;
• R represents a hydrocarbyl aromatic structure or ferrocene structure having at least one aromatic ring to which Q1 and Q2 are each linked, via the respective linking group, on two available adjacent cyclic atoms of the at least one aromatic ring and which is substituted with one or more substituent(s) Yi on one or more further aromatic cyclic atom(s) of R;
• wherein immediately adjacent cyclic atoms of R on either side of the said two available adjacent cyclic atoms are not substituted;
• wherein the substituent(s) Yi on the aromatic structure together have a total number Σti of atoms other than hydrogen such that Σti is greater than or equal to 4, wherein ti represents the number of atoms other than hydrogen on a particular substituent Yi;
• wherein the groups X1, X2, X3 and X4 independently represent univalent radicals of up to 30 atoms having at least one tertiary carbon atom or X1 and X2 together, X3 and X4 together, or X1 and X2 and X3 and X4 together form a bivalent radical of up to 40 atoms having at least two tertiary carbon atoms wherein each said univalent or bivalent radical is joined via said at least one or two tertiary carbon atoms respectively to the respective atom Q1 or Q2;
• and
• wherein Q1 and Q2 each independently represent phosphorus, arsenic or antimony;
• wherein each Yi independently represents —SR40R41R42;
• wherein S is selected from Si or C;
• wherein R40, R41 and R42 are independently selected from C1 to C10 alkyl or five-to-ten-membered carbocyclic aryl;
• wherein n is the total number of substituent(s) Yi;
• and
• wherein i ranges from 1 to n,
• wherein the hydrocarbyl aromatic structure R(Yi)n is selected from 4-t-alkylbenzene-1,2-diyl, 5-t-alkylbenzene-1,2-diyl, 4,5-di-t-alkylbenzene-1,2-diyl, 4,5-di-t-butyl-benzene-1,2-diyl, 4-t-butylbenzene-1,2-diyl, 5-t-butylbenzene-1,2-diyl, 2-t-alkyl-naphthalene-8,9-diyl, 3-t-alkyl-naphthalene-8,9-diyl, 4-t-alkyl-naphthalene-8,9-diyl, 5-t-alkyl-naphthalene-8,9-diyl, 2,3-di-t-alkyl-naphthalene-8,9-diyl, 2,4-di-t-alkyl-naphthalene-8,9-diyl, 2,5-di-t-alkyl-naphthalene-8,9-diyl, 3,5-di-t-alkyl-naphthalene-8,9-diyl, 4,5-di-t-alkyl-naphthalene-8,9-diyl, 2,3,4-tri-t-alkyl-naphthalene-8,9-diyl, 2,3,5-tri-t-alkyl-naphthalene-8,9-diyl, 2,4,5-tri-t-alkyl-naphthalene-8,9-diyl, 3,4,5-tri-t-alkyl-naphthalene-8,9-diyl, 2,3,4,5-tetra-t-alkyl-naphthalene-8,9-diyl, 1,3-bis(trimethylsilyl)-isobenzofuran-5,6-diyl, 4-(trimethylsilyl)-benzene-1,2-diyl, 4-(2′-phenylprop-2′-yl)-benzene-1,2-diyl, 4-di-t-butyl-methylsilyl-benzene-1,2-diyl, 4-(t-butyldimethylsilyl)-benzene-1,2-diyl, 4-t-butylsilyl-benzene-1,2-diyl, 4-(tri-t-butylsilyl)-benzene-1,2-diyl, 4-(2′-tert-butylprop-2′-yl)benzene-1,2-diyl, 4-(2′,2′,3′,4′,4′-pentamethyl-pent-3′-yl)-benzene-1,2-diyl, 4-t-alkylferrocene-1,2-diyl, 1′-t-alkylferrocene-1,2-diyl, 4,5-di-t-butyl-ferrocene-1,2-diyl, 4-t-butylferrocene-1,2-diyl, 1′-t-butylferrocene-1,2-diyl, 4-(trimethylsilyl)-ferrocene-1,2-diyl, 1′-(trimethylsilyl)-ferrocene-1,2-diyl, 4-(2′-phenylprop-2′-yl)-ferrocene-1,2-diyl, 1′-(2′-phenylprop-2′-yl)-ferrocene-1,2-diyl, 4-di-t-butyl,methylsilyl-ferrocene-1,2-diyl, 1′-di-t-butyl,methylsilyl-ferrocene-1,2-diyl, 4-(t-butyldimethylsilyl)-ferrocene-1,2-diyl, 1′-(t-butyldimethylsilyl)-ferrocene-1,2-diyl, 4-(tri-t-butylsilyl)-ferrocene-1,2-diyl, 1′-(tri-t-butylsilyl)-ferrocene-1,2-diyl, 4-(2′-tert-butylprop-2′-yl)ferrocene-1,2-diyl, 1′-(2′-tert-butylprop-2′-yl)ferrocene-1,2-diyl, 4-(2′,2′,3′,4′,4′ pentamethyl-pent-3′-yl)-ferrocene-1,2-diyl, or 1′-(2′,2′,3′,4′,4′ pentamethyl-pent-3′-yl)-ferrocene-1,2-diyl.

A process for the carbonylation of ethylenically unsaturated compounds comprising reacting said compound with carbon monoxide in the presence of a source of hydroxyl groups and of a catalyst system, the catalyst system obtainable by combining:

• (a) palladium or a compound thereof:
• and
• (b) a bidentate ligand of general formula (I)
• wherein:
• A and B represent C0 or a methylene group wherein by C0 is meant that the group Q1 or Q2 is connected directly to the R group and there is no methylene group and in this case the other group cannot be C0 and must be a methylene group and, therefore, at least one of A and B is a methylene group;
• R represents a hydrocarbyl aromatic structure or ferrocene having at least one aromatic ring to which Q1 and Q2 are each linked, via the respective linking group when the latter is present, on two available adjacent cyclic atoms of the at least one aromatic ring and which is substituted with one or more substituent(s) Yi on one or more further aromatic cyclic atom(s) of R;
• wherein immediately adjacent cyclic atoms of R on either side of the said two available adjacent cyclic atoms are not substituted;
• wherein the substituent(s) Yi on the aromatic structure together have a total number Σti of atoms other than hydrogen such that Σti is greater than or equal to 4, wherein ti represents the number of atoms other than hydrogen on a particular substituent Yi;
• wherein the groups X1, X2, X3 and X4 independently represent univalent radicals of up to 30 atoms having at least one tertiary carbon atom or X1 and X2 together, X3 and X4 together or X1 and X2 and X3 and X4 together form a bivalent radical of up to 40 atoms having at least two tertiary carbon atoms wherein each said univalent or bivalent radical is joined via said at least one or two tertiary carbon atoms respectively to the respective atom Q1 or Q2;
• and
• wherein Q1 and Q2 each independently represent phosphorus, arsenic or antimony;
• wherein each Yi independently represents —SR40R41R42;
• wherein S is selected from Si or C;
• wherein R40, R41 and R42 are independently selected from C1 to C10 alkyl or five-to-ten-membered carbocyclic aryl
• wherein n is the total number of substituent(s) Yi;
• wherein i ranges from 1 to n;
• and, optionally, a source of anions.

A catalyst system obtainable by combining

• (a) palladium or a compound thereof:
• and
• (b) a bidentate ligand of general formula (I)
• wherein:
• A and B represent Co or a methylene group wherein by Co is meant that the group Q1 or Q2 is connected directly to the R group and there is no methylene group and in this case the other group cannot be Co and must be a methylene group and, therefore, at least one of A and B is a methylene group;
• R represents a hydrocarbyl aromatic structure or ferrocene structure having at least one aromatic ring to which Q1 and Q2 are each linked, via the respective linking group, on two available adjacent cyclic atoms of the at least one aromatic ring and which is substituted with one or more substituent(s) Yi on one or more further aromatic cyclic atom(s) of R;
• wherein immediately adjacent cyclic atoms of R on either side of the said two available adjacent cyclic atoms are not substituted;
• wherein the substituent(s) Yi on the aromatic structure together have a total of atoms other than hydrogen such that Σti is greater than or equal to 4, wherein ti represents the number of atoms other than hydrogen on a particular substituent Yi;
• wherein the groups X1, X2, X3 and X4 independently represent univalent radicals of up to 30 atoms having at least one tertiary carbon atom or X1 and X2 together, X3 and X4 together or X1 and X2 and X3 and X4 together form a bivalent radical of up to 40 atoms having at least two tertiary carbon atoms wherein each said univalent or bivalent radical is joined via said at least one or two tertiary carbon atoms respectively to the respective atom Q1 or Q2;
• and
• wherein Q1 and Q2 each independently represent phosphorus, arsenic or antimony;
• wherein each Yi independently represents —SR40R41R42;
• wherein S is selected from Si or C;
• wherein R40, R41 and R42 are independently selected from C1 to C10 alkyl or five-to-ten-membered carbocyclic aryl;
• wherein n is the total number of substituent(s) Yi;
• and
• wherein i ranges from 1 to n;
• and, optionally, a source of anions.