Arylation of olefins
View Patent ↗The present invention relates to a process for the arylation of olefins by reaction of haloaromatics or arylsulfonates with olefins in the presence of a palladium catalyst, a bulky nitrogen base and a dipolar aprotic solvent.
1. Process for preparing arylolefins, comprising reacting aromatic compounds of the general formula (I),
Ar—[X] n (I),
where
n is one or two and
Ar is a substituted or unsubstituted aromatic radical and
X are each, independently of one another, chlorine, bromine, iodine or a sulphonate,
with olefins which bear at least one hydrogen atom on the double bond
in the presence of a palladium catalyst,
at least one bulky nitrogen base and
in the presence of a dipolar aprotic solvent,
wherein the bulky nitrogen bases used are amines of the general formula,
NR 8 R 9 R 10 (VII)
where
R 8 , R 9 and R 10 are each, independently of one another, C 1 -C 20 -alkyl, C 5 -C 14 -aryl or C 6 -C 15 -arylalkyl or two or three of the radicals R 8 , R 9 and R 10 together with the nitrogen atom may form a monocyclic, bicyclic or tricyclic heterocycle having from 4 to 8 carbon atoms per ring,
with the proviso that one, two or three of the radicals R 8 , R 9 and R 10 , are each, independently of one another, either bound to the nitrogen atom via a tertiary or quaternary sp 3 carbon atom or are an aryl radical which is monosubstituted or disubstituted, in the ortho positions or
N-heteroaromatic compounds which are substituted in the two ortho positions relative to the nitrogen.
2. Process according to claim 1 , wherein the dipolar aprotic solvents used are amide solvents, sulphoxides, nitriles, ketones or sulpholanes or mixtures thereof.
3. Process according to claim 1 , wherein the dipolar aprotic solvents used are dimethylformamide, dimethylacetamide, N-methylpyrrolidone or mixtures thereof.
4. Process according to claim 1 , wherein the general formula (I),
Ar is a carbocyclic aromatic radical having from 6 to 24 framework carbon atoms or a heteroaromatic radical having from 5 to 24 framework carbon atoms in which no, one, two or three framework carbon atoms per ring, but at least one framework carbon atom in the total molecule, is/are replaced by heteroatoms selected from the group consisting of nitrogen, sulphur and oxygen, where
the carbocyclic aromatic radical or heteroaromatic radical is substituted by up to five identical or different substituents per ring selected from the group consisting of hydroxy, fluoro, nitro, cyano, free or protected formyl, C 1 -C 12 -alkyl, C 5 -C 14 -aryl, C 6 -C 15 -arylalkyl, —PO—[(C 1 -C 8 )-alkyl] 2 , —PO—[(C 5 -C 14 )-aryl] 2 , —PO—[(C 1 -C 8 )-alkyl)(C 5 -C 14 )-aryl)], tri(C 1 -C 8 -alkyl)siloxyl and radicals of the general formula (II),
A—B—D—E (II)
where, independently of one another,
A is absent or is a C 1 -C 8 -alkylene radical and
B is absent or is oxygen, sulphur or NR 1 ,
where R 1 is hydrogen, C 1 -C 8 -alkyl, C 6 -C 15 -arylalkyl or C 5 -C 14 -aryl and
D is a carbonyl group and
E is R 2 , OR 2 , NHR 3 or N(R 3 ) 2 ,
where R 2 is C 1 -C 8 -alkyl, C 6 -C 15 -arylalkyl, C 1 -C 8 -haloalkyl or C 5 -C 14 -aryl and
R 3 are each, independently of one another, C 1 -C 8 -alkyl, C 6 -C 15 -arylalkyl or C 6 -C 14 -aryl or the moiety N(R 3 ) 2 is a cyclic amino radical,
and radicals of the general formulae (IIIa-e)
A—E (IIIa)
A—SO 2 —E (IIIb)
A—B—SO 2 R 2 (IIIc)
A—SO 3 W (IIId)
A—COW (IIIe)
where A, B, E and R 2 are as defined above and W is OH, NH 2 , or OM, where M is an alkali metal ion, half an equivalent of an alkaline earth metal ion, an
ammonium ion or an organic ammonium ion and
X is chlorine, bromine, iodine, trifluoromethanesulphonyloxy or nonafluorobutanesulphonyloxy.
5. Process according to claim 1 , wherein the palladium catalysts used are palladium complexes.
6. Process according to claim 1 , wherein the palladium catalysts used are palladium complexes which are generated in the reaction solution from palladium compounds and phosphorus compounds.
7. Process according to claim 6 , wherein the phosphorus compounds used are monophosphorus compounds of the general formula (Va),
P(E—R4) 3 (Va)
where
E are each, independently of one another and independently of R4, absent or oxygen and
the radicals R4 are each, independently of one another, C 1 -C 8 -alkyl or unsubstituted phenyl, naphthyl or ferrocenyl or phenyl, naphthyl or ferrocenyl substituted by one, two or three radicals R5, where
R5 is C 1 -C 8 -alkyl, C 1 -C 8 -alkoxy, chlorine, fluorine, N(C 1 -C 8 -alkyl) 2 , CO 2 —(C 1 -C 6 -alkyl), —CON(C 1 -C 6 -alkyl) 2 , cyano or CO(C 1 -C 6 -alkyl) or
diphosphorus compounds of the general formula (Vb),
(R6—E) 2 P—E—Z—E—P(E—R6) 2 (Vb)
where
E are each, independently of one another and independently of R6 and Z, absent or oxygen and
the radicals R6 are each, independently of one another, C 1 -C 8 -alkyl or phenyl, naphthyl or heteroaryl having from 5 to 12 framework carbon atoms which may be unsubstituted or substituted by one, two or three radicals R7, where
R7 are selected independently from the group consisting of C 1 -C 8 -alkyl, C 1 -C 8 -alkoxy, fluorine and cyano and
Z is an unsubstituted or substituted radical selected from the group consisting of C 1 -C 4 -alkylene, 1,2-phenylene, 1,3-phenylene, 1,2-cyclohexylene, 1,1′-ferrocenylene, 1,2-ferrocenylene, 2,2′-(1,1′-binaphthylene) and 1,1′-biphenylene.
8. Process according to claim 6 , wherein the phosphorus compounds used are tri(tert-butyl)phosphine, phenyldi(tert-butyl)phosphine and ferrocenyldi(tert-butyl)phosphine.
9. Process according to claim 6 , wherein the molar ratio of phosphorus to palladium in the reaction mixture is from 1:1 to 100:1.
10. Process according to claim 1 , wherein the molar ratio of X in compounds of the general formula (I) to palladium is from 10 to 20 000.
11. Process according to claim 1 , wherein the bulky nitrogen bases used are dicyclohexylmethylamine, dicyclohexylethylamine, cyclohexyldiethylamine and cyclohexyldimethylamine.
12. Process according to claim 1 , wherein the olefins bearing at least one hydrogen atom on the double bond are olefins of the general formula (X),
R 11 CH═CR 12 R 13 (X)
where, independently of one another,
R 11 is hydrogen or methyl and
R 12 is hydrogen or methyl and
R 13 is hydrogen, cyano, SO 3 M, C 1 -C 8 -alkyl, a carbocyclic aromatic radical having from 6 to 18 framework carbon atoms or a heteroaromatic radical having from 5 to 18 framework carbon atoms in which no, one, two or three framework carbon atoms per ring, but at least one framework carbon atom in the total molecule, may be replaced by heteroatoms selected from the group consisting of nitrogen, sulphur and oxygen or a radical of the general formula (XI)
where
G is one of OM, OH, NH 2 , OR 14 , NHR 14 and N(R 14 ) 2 ,
and R 14 is C 1 -C 12 -alkyl, C 6 -C 15 -arylalkyl or C 6 -C 10 -aryl or
the N(R 14 ) 2 and M is an alkali metal ion, half an equivalent of an alkaline earth metal ion, an ammonium ion or an organic ammonium ion is a cyclic amino radical.
13. Process according to claim 1 , wherein the reaction temperature is from 20° C. to 200° C.