Metal complexes for use in olefin metathesis and atom group transfer reactions
AssigneeUniversiteit Gent
InventorsFrancis Walter Verpoort, Renata Drozdzak, Nele Ledoux, Bart Allaert
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Abstract
Improved catalysts useful in a number of organic synthesis reactions such as olefin metathesis and atom or group transfer reactions are made by bringing into contact a multi-coordinated metal complex comprising a multidentate Schiff base ligand, and one or more other ligands, with an acid under conditions such that said acid is able to at least partly cleave a bond between the metal and the multidentate Schiff base ligand of said metal complex, optionally through intermediate protonation of said Schiff base ligand.
Claims47
1-57. (canceled)
A method of modifying a multi-coordinated metal, a salt, a solvate or an enantiomer thereof, said multi-coordinated metal complex comprising (i) at least one multidentate Schiff base ligand comprising an imino group and being coordinated to the metal, in addition to the nitrogen atom of said imino group, through at least one further heteroatom selected from the group consisting of oxygen, sulfur and selenium, and (ii) one or more other ligands, said method comprising bringing said multi-coordinated metal complex into contact with an acid under conditions such that said acid is able to at least partly cleave a bond between the metal and said at least one multidentate Schiff base ligand (i), and wherein said other ligands (ii) are selected such as to be unable of protonation by said acid under said conditions, and are not selected from the group consisting of phosphines, amines, arsines and stibines.
A reaction product of:
- (a) a multi-coordinated metal complex, a salt, a solvate or an enantiomer thereof, said multi-coordinated metal complex comprising (i) at least one multidentate Schiff base ligand comprising an imino group and being coordinated to the metal, in addition to the nitrogen atom of said imino group, through at least one further heteroatom selected from the group consisting of oxygen, sulfur and selenium, and (ii) one or more other ligands, and
- (b) an acid reacted in a molar ratio above about 1.2 with respect to said multi-coordinated metal complex (a),
- provided that said other ligands (ii) are unable of protonation by said acid and are not selected from the group consisting of amines, phosphines, arsines and stibines.
A catalytic system comprising:
- as the main catalytic species, a reaction product of:
- (a) a multi-coordinated metal complex, a salt, a solvate or an enantiomer thereof, said multi-coordinated metal complex comprising (i) at least one multidentate Schiff base ligand comprising an imino group and being coordinated to the metal, in addition to the nitrogen atom of said imino group, through at least one further heteroatom selected from the group consisting of oxygen, sulfur and selenium, and (ii) one or more other ligands, and
- (b) an acid reacted in a molar ratio above about 1.2 with respect to said multi-coordinated metal complex (a),
- provided that said other ligands (ii) are unable of protonation by said acid and are not selected from the group consisting of amines, phosphines, arsines and stibines;
- and
- one or more second catalyst components being selected from the group consisting of Lewis acid co-catalysts (b1), catalyst activators (b2), and initiators having a radically transferable atom or group (b3).
Dependencies are inferred from the claim text.