Methods for preparing ruthenium carbene complexes and precursors thereto
Methods of preparing ruthenium carbene complex precursors are disclosed herein. In some embodiments, the methods include reacting a ruthenium refinery salt with an L-type ligand and a reducing agent to form the ruthenium carbene complex precursor. Methods of preparing a ruthenium vinylcarbene complex are also disclosed. In some embodiments, preparing a ruthenium carbene complex includes converting a ruthenium carbene complex precursor into a ruthenium carbene complex having a structure (PR 1 R 2 R 3 ) 2 Cl 2 Ru═CH—R 4 , wherein R 1 , R 2 , R 3 , and R 4 are defined herein.
1. A method for preparing a ruthenium vinylcarbene complex comprising:
reacting a ruthenium refinery salt with a L-type ligand and a reducing agent to form a ruthenium carbene complex precursor, the ruthenium refinery salt being an ammonium salt of a halogen-containing ruthenium complex, wherein the halogen-containing ruthenium complex comprises chlorine, and where the L-type ligand comprises a cyclic olefin;
converting the ruthenium carbene complex precursor into a ruthenium hydrido halide complex; and
reacting the ruthenium hydrido halide complex with a propargyl halide to form the ruthenium vinylcarbene complex.
2. The method of claim 1 , wherein the converting comprises reacting the ruthenium carbene complex precursor with a trialkyl phosphine, hydrogen, and a trialkyl amine.
3. The method of claim 1 , wherein the ruthenium hydrido halide complex comprises a compound having a structure [Ru(H)(H 2 )X(PR 1 R 2 R 3 ) 2 ];
wherein X is a halide;
wherein R 1 , R 2 , and R 3 are alike or different and are each independently selected from the group consisting of substituted or unsubstituted aryl, substituted or unsubstituted C 1 -C 10 alkyl, substituted or unsubstituted aryloxy, substituted or unsubstituted C 1 -C 10 alkoxy, and combinations thereof; and
wherein covalent bonds may optionally exist between two or more of R 1 , R 2 , and R 3 ; and
wherein any two of R 1 , R 2 , and R 3 taken together may optionally form a ring with phosphorus.
4. The method of claim 3 , further comprising replacing a phosphine ligand of the ruthenium vinylcarbene complex with an N-heterocyclic carbene ligand.
5. The method of claim 3 , further comprising replacing a phosphine ligand of the ruthenium vinylcarbene complex with an imidazolidine ligand to form an imidazolidine-containing ruthenium vinylcarbene complex.
6. The method of claim 5 , wherein the imidazolidine-containing ruthenium vinylcarbene complex is a second-generation Grubbs-type olefin metathesis catalyst.
7. The method of claim 5 , wherein the imidazolidine ligand comprises 1,3-dimesityl-4,5-dihydroimidazole.
8. The method of claim 1 , wherein the ruthenium hydrido halide complex comprises a compound having a structure [Ru(H)(H 2 )Cl(PCy 3 ) 2 ], and wherein the propargyl halide comprises 3-chloro-3-methyl-1-butyne.
9. The method of claim 8 , wherein the ruthenium vinylcarbene complex comprises a compound having a structure (PCy 3 ) 2 Cl 2 Ru═CH—CH═C(CH 3 ) 2 .