Metathesis catalysts and reactions using the catalysts

1. A method of forming an olefin product in a metathesis reaction from a feedstock comprising a first olefin and a second olefin, wherein said feedstock further comprises at least one by-product selected from the group consisting of water, alcohols, aldehydes, peroxides, hydroperoxides, peroxide decomposition products, protic materials, polar materials, Lewis basic catalyst poisons, and mixtures thereof, the method comprising step (i), and subsequent to step (i), the following step (ii):

(i) at least partially removing said at least one by-product from the feedstock by subjecting said feedstock to (1) a chemical purification step or (2) both a physical purification step and a chemical purification step,

wherein the physical purification step comprises subjecting said feedstock to at least one of a distillation step or an adsorption step; and

wherein the chemical purification step comprises subjecting said feedstock to a chemical reaction wherein said feedstock is subjected to an anhydride of an organic acid or an organometallic compound of aluminum;

(ii) reacting the first olefin with the second olefin in the presence of a compound that catalyzes said metathesis reaction such that the molar ratio of said compound to the first or the second olefin is less than 1:500, and the conversion of the first or the second olefin to said olefin product is at least 30%;

wherein the compound that catalyzes said metathesis reaction has the following general Formula (A):

wherein

M=Mo or W;

R 1 is aryl, heteroaryl, alkyl, or heteroalkyl, each of which is optionally substituted;

R 2 and R 3 are the same or different and are alkyl, alkenyl, heteroalkyl, heteroalkenyl, aryl, or heteroaryl, each of which is optionally substituted, or hydrogen;

R 5 is alkyl, alkoxy, heteroalkyl, aryl, aryloxy, heteroaryl, silylalkyl, silyloxy, each of which is optionally substituted; and

R 4 is a residue R 6 —X—, wherein

X═O and R 6 is aryl, optionally substituted; or

X═S and R 6 is aryl, optionally substituted; or

X═O and R 6 is (R 7 )(R 8 )(R 9 )Si; wherein R 7 , R 8 , R 9 are alkyl or phenyl, each of which is optionally substituted; or

X═O and R 6 is (R 10 )(R 11 )(R 12 )C, wherein R 10 , R 11 , R 12 are independently selected from optionally substituted phenyl or optionally substituted alkyl; or

X═O and R 6 is a quinoline-8-yl, optionally substituted; or

X═O and R 6 is triphenylmethyl; tri(4-methyphenyl)methyl; 1,1,1,3,3,3-hexafluoro-prop-2-yl; or 9-phenyl-fluorene-9-yl; or

R 4 and R 5 are linked together and are bound to M via oxygen, respectively;

or wherein the compound that catalyzes said metathesis reaction is selected from one of the following structures: 280, 281, 289, 290, or 291:

wherein the organometallic compound of aluminum of step (i) is of formula R 1 R 2 R 3 Al, wherein said R 1 , R 2 , and R 3 in the organometallic compound of aluminum are independently selected from aliphatic, cyclic, or alicyclic residues having from 1 to 10 carbon atoms, or from aromatic residues having from 6 to 10 carbon atoms; and

wherein said chemical reaction further comprises:

(a) determining an amount of said at least one by-product in the feedstock, wherein said at least one by-product comprises at least one reactive group, wherein said at least one reactive group is reactive towards said compound that catalyzes said metathesis reaction and with said anhydride of an organic acid or said organometallic compound of aluminum; and

adding a theoretical amount of either said anhydride of an organic acid or said organometallic compound of aluminum, respectively, that is needed to convert said at least one reactive group into at least one non-reactive group, wherein said at least one non-reactive group is not reactive towards said compound that catalyzes said metathesis reaction and either said anhydride of an organic acid or said organometallic compound of aluminum; or

(b) adding an excess of said anhydride of an organic acid or said organometallic compound of aluminum per mole of said at least one by-product to convert said at least one by-product into a species which is not reactive towards the compound that catalyzes said metathesis reaction.

2. The method of claim 1 , wherein the organometallic compound of aluminum is trioctyl aluminum.

3. The method of claim 1 , wherein the organometallic compound of aluminum is a trialkyl aluminum compound, and wherein the feedstock is subjected to the trialkyl aluminum compound for a period of from 10 to 80 h.

4. The method of claim 1 , wherein the feedstock is subjected to the organometallic compound of aluminum, and wherein the organometallic compound of aluminum is added to the first and the second olefin at a rate of from 0.01 to 10 ppmwt organometallic compound of aluminum per hour.

5. The method of claim 1 , wherein in the compound of general Formula (A):

M=Mo or W;

R 1 is aryl or adamant-1-yl, each of which is optionally substituted;

R 2 is —C(CH 3 ) 2 C 6 H 5 or —C(CH 3 ) 3 ;

R 3 is H;

R 5 is alkoxy, heteroaryl, silyloxy, or aryloxy, each of which is optionally substituted; and

R 4 is a residue R 6 —X—, wherein

X═O and R 6 is phenyl substituted with up to five substituents independently selected from alkyl, phenoxy, phenyl, halogen, each of which is optionally substituted; or

X═O and R 6 is 8-(naphthalene-1-yl)-naphthalene-1-yl, optionally substituted; or

X═O and R 6 is 8-phenlynaphthalene-1-yl, optionally substituted; or

X═O and R 6 is quinoline-8-yl, optionally substituted; or

X═S and R 6 is phenyl substituted with up to five substituents independently selected from alkyl, phenoxy, phenyl, halogen, each of which is optionally substituted; or

X═O and R 6 is triphenylsilyl, optionally substituted; or triisopropylsilyl; or

X═O and R 6 is triphenylmethyl, optionally substituted; or

X═O and R 6 is 9-phenyl-fluorene-9-yl; or

X═O and R 6 is 2-phenyl-1,1,1,3,3,3-hexafluoro-prop-2-yl, or 2-methyl-1,1,1,3,3,3-hexafluoro-prop-2-yl; or

X═O and R 6 is t-butyl;

or

wherein in the compound of general Formula (A):

M=Mo or W;

R 1 is selected from 1-(2,6-dimethylphenyl), 1-(2,6-diisopropylphenyl), 1-(2,6-di-t-butylphenyl), 1-(2,6-dichlorophenyl), adamant-1-yl;

R 2 is —C(CH 3 ) 2 C 6 H 5 or —C(CH 3 ) 3 ;

R 3 is H;

R 5 is selected from pyrrol-1-yl; 2,5-dimethyl-pyrrol-1-yl; triphenylsilyloxy;

triisopropylsilyloxy; 2-phenyl-1,1,1,3,3,3-hexafluoro-prop-2-yloxy; 2-methyl-1,1,1,3,3,3-hexafluoro-prop-2-yloxy; 9-phenyl-fluorene-9-yloxy; 2,6-diphenylphenoxy; t-butyloxy; and

R 4 is R 6 —X—, wherein

X═O and R 6 is phenyl substituted with up to five substituents independently selected from alkyl, alkoxy, phenoxy, phenyl, halogen, each of which is optionally substituted; or

X═O and R 6 is 8-(naphthalene-1-yl)-naphthalene-1-yl, optionally substituted; or

X═O and R 6 is 8-phenlynaphthalene-1-yl, optionally substituted; or

X═O and R 6 is quinoline-8-yl, optionally substituted; or

X═S and R 6 is phenyl substituted with up to five substituents independently selected from alkyl, phenoxy, phenyl, halogen, each of which is optionally substituted; or

X═O and R 6 is triphenylsilyl; or triisopropylsilyl; or

X═O and R 6 is triphenylmethyl or tri(4-methylphenyl)methyl; or

X═O and R 6 is 9-phenyl-fluorene-9-yl; or

X═O and R 6 is 2-phenyl-1,1,1,3,3,3-hexafluoro-prop-2-yl; or 2-methyl-1,1,1,3,3,3-hexafluoro-prop-2-yl; or

X═O and R 6 is t-butyl.

6. The method of claim 1 , wherein in the compound of general Formula (A):

M=Mo or W;

R 1 is selected from 2,6-dimethylphenyl, 2,6-diisopropylphenyl, 2,6-dichlorophenyl, adamant-1-yl;

R 2 is —C(CH 3 ) 2 C 6 H 5 or —C(CH 3 ) 3 ;

R 3 is H;

R 5 is selected from pyrrol-1-yl; 2,5-dimethyl-pyrrol-1-yl; triphenylsilyloxy; triisopropylsilyloxy; 2-phenyl-1,1,1,3,3,3-hexafluoro-prop-2-yloxy; 2-methyl-1,1,1,3,3,3-hexafluoro-prop-2-yloxy; 9-phenyl-fluorene-9-yloxy; 2,6-diphenylphenoxy; t-butyloxy; and

R 4 is R 6 —X—, wherein

X═O and R 6 is phenyl which bears two substituents in ortho position with respect to O, or which bears at least three substituents, from which two substituents are in ortho position with respect to O and one substituent is in para position with respect to O; or

X═O and R 6 is 8-(naphthalene-1-yl)-naphthalene-1-yl, optionally substituted; or

X═O and R 6 is 8-phenlynaphthalene-1-yl, optionally substituted; or

X═O and R 6 is quinoline-8-yl, optionally substituted; or

X═O and R 6 is triphenylsilyl; or triisopropylsilyl;

X═O and R 6 is triphenylmethyl or tri(4-methylphenyl)methyl; or

X═O and R 6 is 9-phenyl-fluorene-9-yl; or

X═O and R 6 is 2-phenyl-1,1,1,3,3,3-hexafluoro-prop-2-yl; or 2-methyl-1,1,1,3,3,3-hexafluoro-prop-2-yl; or

X═O and R 6 is t-butyl.

7. The method of claim 1 , wherein the compound is selected from the following structures:

8. The method of claim 1 , wherein in the compound of general Formula (A):

M=Mo or W;

R 1 is selected from 2,6-dimethylphenyl, 2,6-diisopropylphenyl, 2,6-di-t-butylphenyl, 2,6-dichlorophenyl, adamant-1-yl;

R 2 is —C(CH 3 ) 2 C 6 H 5 or —C(CH 3 ) 3 ;

R 3 is H;

R 5 is selected from pyrrol-1-yl; 2,5-dimethyl-pyrrol-1-yl; triphenylsilyloxy; triisopropylsilyloxy; 2-phenyl-1,1,1,3,3,3-hexafluoro-prop-2-yloxy; 2-methyl-1,1,1,3,3,3-hexafluoro-prop-2-yloxy; 9-phenyl-fluorene-9-yloxy; 2,6-diphenylphenoxy; t-butoxy; and

R 4 is R 6 —X—, wherein

X═O and R 6 is phenyl which bears at least two substituents, or which bears two substituents in ortho position with respect to O, or which bears two substituents in ortho position with respect to O and a substituent in para position with respect to O; or

X═O and R 6 is triphenylsilyl, optionally substituted; or

X═O and R 6 is triphenylmethyl, optionally substituted; or

X═O and R 6 is 9-phenyl-fluorene-9-yl; or

X═O and R 6 is 2-phenyl-1,1,1,3,3,3-hexafluoro-prop-2-yl or 2-methyl-1,1,1,3,3,3-hexafluoro-prop-2-yl; or

X═O and R 6 is t-butyl;

with the proviso that the following compounds are excluded:

M=Mo; R 1 =2,6-diisopropylphenyl; R 2 =—C(CH 3 ) 2 C 6 H 5 ; R 3 ═H; R 5 =2,5-dimethylpyrrol-1-yl; R 4 =2,6-diphenylphenoxy;

M=Mo; R 1 =2,6-diisopropylphenyl; R 2 =—C(CH 3 ) 2 C 6 H 5 ; R 3 ═H; R 5 =2,5-dimethylpyrrol-1-yl; R 4 =2,3,5,6-tetraphenylphenoxy;

M=W; R 1 =2,6-diisopropylphenyl; R 2 =—C(CH 3 ) 2 C 6 H 5 ; R 3 ═H; R 5 =2,5-dimethylpyrrol-1-yl; R 4 =triphenylsilyloxy;

M=Mo; R 1 =2,6-diisopropylphenyl; R 2 =—C(CH 3 ) 2 C 6 H 5 ; R 3 ═H; R 5 =2,5-dimethylpyrrol-1-yl; R 4 =triphenylsilyloxy; and

M=W; R 1 =2,6-diisopropylphenyl; R 2 =—C(CH 3 ) 2 C 6 H 5 ; R 3 ═H; R 5 =2,5-dimethylpyrrol-1-yl;

R 4 =

wherein TBS is t-butyldimethylsilyl,

and

wherein R 19 is F, Cl, Br, or I;

or

wherein

M=Mo or W;

R 1 is selected from 2,6-dimethylphenyl, 2,6-diisopropylphenyl, 2,6-dichlorophenyl, adamant-1-yl;

R 2 is —C(CH 3 ) 2 C 6 H 5 or —C(CH 3 ) 3 or adamant-1-yl;

R 3 is H;

R 5 is selected from pyrrol-1-yl; 2,5-dimethyl-pyrrol-1-yl; triphenylsilyoxy; 2-phenyl-1,1,1,3,3,3-hexafluoro-prop-2-yloxy; 9-phenyl-fluorene-9-yloxy; and

R 4 is selected from

wherein TBS is t-butyldimethylsilyl;

wherein Me=methyl;

or

wherein

M=Mo or W;

R 1 is 2,6-dimethylphenyl, 2,6-diisopropylphenyl, 2,6-dichlorophenyl, adamant-1-yl;

R 2 is —C(CH 3 ) 2 C 6 H 5 or —C(CH 3 ) 3 or adamant-1-yl;

R 3 is H;

R 5 is selected from pyrrol-1-yl; 2,5-dimethyl-pyrrol-1-yl; triphenylsilyloxy; 2-phenyl-1,1,1,3,3,3-hexafluoro-prop-2-yloxy; 9-phenyl-fluorene-9-yloxy; and

R 4 is selected from 2,6-diphenylphenoxy, 2,3,5,6-tetraphenylphenoxy, 2,6-di(tert-butyl)phenoxy; 2,6-di(2,4,6-triisopropylphenyl)phenoxy;

with the proviso that the following compounds are excluded:

M=Mo; R 1 =2,6-diisopropylphenyl; R 2 =—C(CH 3 ) 2 C 6 H 5 ; R 3 ═H; R 5 =2,5-dimethylpyrrol-1-yl; R 4 =2,6-diphenylphenoxy; and

M=Mo; R 1 =2,6-diisopropylphenyl; R 2 =—C(CH 3 ) 2 C 6 H 5 ; R 3 ═H; R 5 =2,5-dimethylpyrrol-1-yl; R 4 =2,3,5,6-tetraphenylphenoxy;

or

wherein

M=Mo or W;

R 1 is selected from 2,6-dimethylphenyl, 2,6-diisopropylphenyl, 2,6-dichlorophenyl, adamant-1-yl;

R 2 is —C(CH 3 ) 2 C 6 H 5 or —C(CH 3 ) 3 or adamant-1-yl;

R 3 is H;

R 5 is selected from pyrrol-1-yl; 2,5-dimethyl-pyrrol-1-yl; triphenylsilyloxy; 2-phenyl-1,1,1,3,3,3-hexafluoro-prop-2-yloxy; 9-phenyl-fluorene-9-yloxy; and

R 4 is a residue R 6 —X—, wherein X═O and R 6 is triphenylsilyl;

with the proviso that following compounds are excluded:

M=W; R 1 =2,6-diisopropylphenyl; R 2 =—C(CH 3 ) 2 C 6 H 5 ; R 3 ═H; R 5 =2,5-dimethylpyrrol-1-yl; R 4 =triphenylsilyloxy; and

M=Mo; R 1 =2,6-diisopropylphenyl; R 2 =—C(CH 3 ) 2 C 6 H 5 ; R 3 ═H; R 5 =2,5-dimethylpyrrol-1-yl; R 4 =triphenylsilyloxy;

or

wherein

M=Mo or W;

R 1 is selected from 2,6-dimethylphenyl, 2,6-diisopropylphenyl, 2,6-dichlorophenyl, adamant-1-yl;

R 2 is —C(CH 3 ) 2 C 6 H 5 or —C(CH 3 ) 3 or adamant-1-yl;

R 3 is H;

R 5 is selected from pyrrol-1-yl; 2,5-dimethyl-pyrrol-1-yl; triphenylsilyloxy; 2-phenyl-1,1,1,3,3,3-hexafluoro-prop-2-yloxy; 9-phenyl-fluorene-9-yloxy; and

R 4 is a residue R 6 —X—, wherein

X═O and R 6 is triphenylmethyl; tri(4-methyphenyl)methyl; 1,1,1,3,3,3-hexafluoro-prop-2-yl; or 9-phenyl-fluorene-9-yl.

9. The method of claim 1 , wherein in the compound of general Formula (A):

M=Mo or W;

R 1 is aryl, heteroaryl, alkyl, or heteroalkyl, each of which is optionally substituted;

R 2 and R 3 are the same or different and are alkyl, alkenyl, heteroalkyl, heteroalkenyl, aryl, or heteroaryl, each of which is optionally substituted, or hydrogen;

R 5 is alkyl, alkoxy, heteroalkyl, aryl, aryloxy, heteroaryl, silylalkyl, silyloxy, each of which is optionally substituted; and

R 4 is a residue R 6 —X—, wherein

X═O and R 6 is a phenyl ring which is at least substituted in 4-position with respect to O.

10. The method of claim 9 , wherein the substituent of residue R 6 in 4-position is selected from the group consisting of: halogen, dialkylamino, cyano, optionally substituted alkyl, optionally substituted alkyloxy, optionally substituted aryl, optionally substituted aryloxy;

wherein further substituents of residue R 6 are the same or are different from the substituent in 4-position and are independently selected from the group consisting of: halogen, dialkylamino, cyano, optionally substituted alkyl, optionally substituted alkyloxy, optionally substituted aryl, optionally substituted aryloxy;

or wherein

R 1 is phenyl or alkyl, each of which is optionally independently substituted with halogen, C 1-4 dialkylamino, C 1-4 alkyl, C 1-4 alkyloxy, phenyl, phenyloxy, each of which is optionally substituted;

R 2 and R 3 are the same or different and are hydrogen, C(CH 3 ) 3 , or C(CH 3 ) 2 C 6 H 5 ;

R 5 is selected from pyrrol-1-yl; 2,5-dimethyl-pyrrol-1-yl; triphenylsilyloxy; triisopropylsilyloxy, 2-phenyl-1,1,1,3,3,3-hexafluoro-prop-2-yloxy; 2-methyl-1,1,1,3,3,3-hexafluoro-prop-2-yloxy; 2,6-diphenylphenoxy; 9-phenyl-fluorene-9-yloxy; t-butyloxy; and

the substituent of residue R 6 in 4-position is selected from the group consisting of:

halogen, C 1-4 dialkylamino, C 1-4 alkyl, C 1-4 alkyloxy, phenyl, phenyloxy, each of which is optionally substituted;

and further substituents of residue R 6 are the same or are different from the substituent in 4-position and are independently selected from the group consisting of halogen, C 1-4 dialkylamino, C 1-4 alkyl, C 1-4 alkyloxy, phenyl, phenyloxy, each of which is optionally substituted;

or

wherein R 6 is a phenyl ring which is substituted in 2- and 4-position independently with halogen and in 6-position with phenyl, which optionally is substituted with halogen, alkyl, alkyloxy, phenyl, phenoxy; or phenyl or phenoxy optionally substituted with halogen, alkyl, alkyloxy, phenyl, phenoxy, respectively;

or

wherein R 6 is a phenyl ring which is substituted in 2- and 6-position by substituents via carbon atoms, and in 4-position by a substituent via any atom;

or

wherein R 6 is a phenyl ring which is substituted in 4-position with bromine and in 2-, 3-, 5- and 6-position with phenyl, respectively, wherein said phenyl residues are independently substituted with fluoro, chloro, bromo, dimethylamino, diethylamino, methyl, ethyl, propyl, isopropyl, butyl, t-butyl, methoxy, ethoxy, propyloxy, butyloxy, t-butyloxy, trifluoromethyl, phenyl optionally substituted with halogen, alkyl, alkyloxy, phenyl, phenoxy; phenoxy optionally substituted with halogen, alkyl, alkyloxy, phenyl, phenoxy.

11. The method of claim 1 , wherein in the compound of general Formula (A):

M=Mo or W;

R 1 is aryl, heteroaryl, alkyl, or heteroalkyl, each of which is optionally substituted;

R 2 and R 3 are the same or different and are alkyl, alkenyl, heteroalkyl, heteroalkenyl, aryl, or heteroaryl, each of which is optionally substituted, or hydrogen;

R 5 is alkyl, alkoxy, heteroalkyl, aryl, aryloxy, heteroaryl, silylalkyl, silyloxy, each of which is optionally substituted; and

R 4 is a residue R 6 —X—, wherein

X═O and R 6 is a phenyl ring which is substituted in 2- and 6-position with phenyl, respectively, optionally substituted;

or

wherein in the compound of general Formula (A):

M=Mo or W;

R 1 is aryl, heteroaryl, alkyl, or heteroalkyl, each of which is optionally substituted;

R 2 and R 3 are the same or different and are alkyl, alkenyl, heteroalkyl, heteroalkenyl, aryl, or heteroaryl, each of which is optionally substituted, or hydrogen;

R 5 is alkyl, alkoxy, heteroalkyl, aryl, aryloxy, heteroaryl, silylalkyl, silyloxy, each of which is optionally substituted; and

R 4 is [8-(naphthalene-1-yl)-naphthalene-1-yl]oxy, optionally substituted;

or

wherein in the compound of general Formula (A):

M=Mo or W;

R 1 is aryl, heteroaryl, alkyl, or heteroalkyl, each of which is optionally substituted;

R 2 and R 3 are the same or different and are alkyl, alkenyl, heteroalkyl, heteroalkenyl, aryl, or heteroaryl, each of which is optionally substituted, or hydrogen;

R 5 is alkyl, alkoxy, heteroalkyl, aryl, aryloxy, heteroaryl, silylalkyl, silyloxy, each of which is optionally substituted; and

R 4 is (8-phenylnaphthalene-1-yl)oxy, optionally substituted.

12. The method of claim 1 , wherein the first olefin has a terminal olefinic double bond, and the second olefin has a terminal olefinic double bond, wherein the first and the second olefin are identical; or

wherein the first and the second olefin are different from one another; or

wherein the first olefin has an internal olefinic double bond and the second olefin is ethylene; or

wherein the first olefin is a cyclic olefin and the second olefin is a cyclic olefin,

wherein the first and the second olefin are identical or are different from one another.

13. A method of increasing the reactivity of a compound of Formula (A):

wherein

M=Mo or W;

R 1 is aryl, heteroaryl, alkyl, or heteroalkyl, each of which is optionally substituted;

R 2 and R 3 are the same or different and are alkyl, alkenyl, heteroalkyl, heteroalkenyl, aryl, or heteroaryl, each of which is optionally substituted, or hydrogen;

R 5 is alkyl, alkoxy, heteroalkyl, aryl, aryloxy, heteroaryl, silylalkyl, silyloxy, each of which is optionally substituted; and

R 4 is a residue R 6 —X—, wherein

X═O and R 6 is aryl, optionally substituted; or

X═S and R 6 is aryl, optionally substituted; or

X═O and R 6 is (R 7 )(R 8 )(R 9 )Si; wherein R 7 , R 8 , R 9 are alkyl or phenyl, each of which is optionally substituted; or

X═O and R 6 is (R 10 )(R 11 )(R 12 )C, wherein R 10 , R 11 , R 12 are independently selected from optionally substituted phenyl, or optionally substituted alkyl;

or

X═O and R 6 is a quinoline-8-yl, optionally substituted; or

R 4 and R 5 are linked together and are bound to M via oxygen, respectively;

or structures 280, 281, 289, 290, or 291:

that catalyzes a metathesis reaction of a feedstock comprising a first and a second olefin such that the molar ratio of said compound to the first or the second olefin is less than 1:500, and the conversion of the first or the second olefin is at least 30%, wherein said feedstock further comprises at least one by-product selected from the group consisting of water, alcohols, aldehydes, peroxides, hydroperoxides, peroxide decomposition products, protic materials, polar materials, Lewis basic catalyst poisons, and mixtures thereof, the method comprising step (i), and, subsequent to step (i), the following step (ii):

(i) at least partially removing said at least one by-product from the feedstock by subjecting said feedstock to a chemical purification step,

wherein the chemical purification step comprises: subjecting said feedstock to a chemical reaction wherein said feedstock is subjected to an anhydride of an organic acid or an organometallic compound of aluminum;

(ii) reacting the first olefin with the second olefin in the presence of said compound that catalyzes said metathesis reaction, and

wherein the organometallic compound of aluminum of step (i) is of formula R 1 R 2 R 3 Al, wherein said R 1 , R 2 , and R 3 in the organometallic compound of aluminum are independently selected from aliphatic, cyclic, or alicyclic residues having from 1 to 10 carbon atoms, or from aromatic residues having from 6 to 10 carbon atoms; and

wherein said chemical reaction further comprises:

(a) determining an amount of said at least one by-product in the feedstock, wherein said at least one by-product comprises at least one reactive group, wherein said at least one reactive group is reactive towards said compound that catalyzes said metathesis reaction and with said anhydride of an organic acid or said organometallic compound of aluminum; and

adding a theoretical amount of either said anhydride of an organic acid or said organometallic compound of aluminum, respectively, that is needed to convert said at least one reactive group into at least one non-reactive group, wherein said at least one non-reactive group is not reactive towards said compound that catalyzes said metathesis reaction and either said anhydride of an organic acid or said organometallic compound of aluminum; or

(b) adding an excess of said anhydride of an organic acid or said organometallic compound of aluminum per mole of said at least one by-product to convert said at least one by-product into a species which is not reactive towards the compound that catalyzes said metathesis reaction.