IONIC METAL ALKYLIDENE COMPOUNDS AND USE THEREOF IN OLEFINIC METATHESIS REACTIONS

1 . A compound of formula I

wherein:

M is selected from Mo or W;

X is selected from O or NR 5 ;

R 1 and R 2 are independently selected from H, C 1-6 alkyl, and aryl; C 1-6 alkyl and aryl optionally being substituted with one or more of C 1-6 alkyl, C 1-6 alkoxy, and O—C 6 H 5 ;

R 3 is selected from a nitrogen-containing aromatic heterocycle being bound to M via said nitrogen; from halogen; and from triflate;

R 4 is an aryl oxy group being bound to M via said oxygen of said aryl oxy group; wherein said aryl group Ar of said aryl oxy group is bound to a group Cat such to form a cationic ligand Cat + -Z—ArO—, wherein Z is either a covalent bond or a linker;

R 5 is alkyl or aryl, optionally substituted; and

Y ⊖ is a non-nucleophilic anion.

2 . The compound of claim 1 , wherein R 1 and R 2 are independently selected from H, C(CH 3 ) 3 , C(CH 3 ) 2 C 6 H 5 , and phenyl substituted in o-position with C 1-6 alkoxy.

3 . The compound of claim 1 , wherein R 3 is selected from pyrrol-1-yl, pyrazol-1-yl, imidazol-1-yl, 1H-1,2,3-triazol-1-yl, 2H-1,2,3-triazol-2-yl, 1H-1,2,4-triazol-1-yl, 4H-1,2,4-triazo-4-yl, indol-1-yl, indazol-1-yl, and azaindol-1-yl, optionally substituted with one or more substituents selected independently from C 1-6 alkyl, C 1-6 alkoxy, phenyl, halogen, or cyano, preferably pyrrol-1-yl, 2,5-dimethylpyrrol-1-yl, and 2,5-diphenylpyrrol-1-yl or indol-1-yl or a substituted indol-1-yl.

4 . The compound of claim 1 , wherein R 3 is selected from halogen.

5 . The compound of claim 1 , wherein said Ar in said Cat + -Z—ArO— is phenyl substituted in 2,6-position with phenyl, optionally substituted, or with isopropyl or t-butyl, respectively; or

said Ar in Cat + -Z—ArO— is phenyl substituted in 4-position with Cat + -Z—; or

said Ar in Cat + -Z—ArO— is phenyl substituted in 2,6 position with phenyl, optionally substituted, or with isopropyl or t-butyl, respectively; and

is substituted in 4-position with Cat + -Z—.

6 . The compound of claim 1 , wherein said group Cat forms together with Z—ArO— a group Cat + -Z—ArO— selected from an ammonium, pyridinium, phosphonium, phosphorinium, arsonium, sulfonium, and oxo sulfonium group, preferably

wherein said R 4 =Cat + -Z—ArO— is a pyridinium N-phenoxy group or a phosphonium P-phenoxy group.

7 . The compound of claim 1 , wherein said R 4 =Cat + -Z—ArO— is selected from the group consisting of

wherein R is H, C(CH 3 ) 3 , CF 3 , phenyl, or C 6 F 13 ;

wherein R is H or CH 3 ;

unsubstituted or substituted with C 1-10 alkyl, optionally substituted with halogen such as fluorine, C 1-10 alkoxy, nitro, cyano, phenyl, phenoxy, N(C 1-6 alkyl) 2 , C(O)N(C 1-6 alkyl) 2 , C(O)NH(C 1-6 alkyl), C(O)O—C 1-6 alkyl, halogen (F, Cl, Br, I) and two or more thereof

wherein P is a protecting group.

8 . The compound of claim 1 , wherein said non-nucleophilic anion Y ⊖ is selected from ClO 4 ⊖ , AsF 6 ⊖ , SbF 6 ⊖ , PF 6 ⊖ , CH 3 SO 3 ⊖ , CF 3 SO 3 ⊖ , p-CH 3 C 6 H 4 SO 3 ⊖ , BF 4 ⊖ , B[3,6-(CF 3 ) 2 C 6 H 3 ] 4 ⊖ , B[C 6 F 5 ] 4 Θ , Al[O-t-C(CH 3 )(CF 3 ) 2 ] ⊖ , and Al[O-t-C(CF 3 ) 3 ] ⊖ .

9 . The compound of claim 1 , wherein the compound of formula I is selected from the group consisting of:

10 . The compound of claim 1 , wherein the compound of formula I does not contain a nitrogen-containing heterocyclic (NHC)-ligand.

11 . A method of making a compound of formula I as defined in claim 1 , the method comprising step (A):

(A) reacting a compound of formula II

with a compound of formula III

[Cat + -Z—ArOH] + Y ⊖    III,

wherein M, X, R 1 , R 2 , R 3 , Y ⊖ , and Cat + -Z—ArO— have the meaning as defined in claim 1 , and R 4 ═R 3 ,

to afford the compound of formula I.

12 . A composition comprising a compound of claim 1 , and a solvent; preferably wherein the solvent is selected from pyrrole, acetonitrile, dimethyl formamide, dimethyl sulfoxide, hexamethylphosphoramide, dimethylacetamide, and sulfolane, and an ionic liquid, or a mixture of two or more thereof, preferably wherein the ionic liquid is selected from

13 . A method of performing a metathesis reaction, comprising step (B):

(B) reacting a first olefin with a second olefin, wherein the first olefin is identical to or different from the second olefin, in the presence of a compound as defined in claim 1 .

14 . The method of claim 13 , wherein the metathesis reaction is performed in the presence of a composition comprising the compound and a further solvent, wherein the further solvent has a lower polarity than pyrrole, acetonitrile, dimethyl formamide, dimethyl sulfoxide, hexamethylphosphoramide, dimethylacetamide, and sulfolane or the ionic liquid such that said pyrrole, acetonitrile, dimethyl formamide, dimethyl sulfoxide, hexamethylphosphoramide, dimethylacetamide, and sulfolane or ionic liquid and the further solvent form two phases.

15 . A method of performing a ring closing metathesis reaction

(a) comprising the use of a compound as defined in claim 1 ; or

(b) comprising the use of a composition comprising the compound of claim 1 ; or

(c) comprising the use of a composition comprising the compound of claim 1 , and a further solvent, wherein the further solvent has a lower polarity than pyrrole, acetonitrile, dimethyl formamide, dimethyl sulfoxide, hexamethylphosphoramide, dimethylacetamide, and sulfolane or the ionic liquid such that said pyrrole, acetonitrile, dimethyl formamide, dimethyl sulfoxide, hexamethylphosphoramide, dimethylacetamide, and sulfolane or ionic liquid and the further solvent form two phases;

preferably wherein the ring closing metathesis reaction is a macrocyclisation.