Synthesis of metal complexes and uses thereof

Abstract

The present disclosure provides novel methods of making aluminum complexes with utility for promoting epoxide carbonylation reactions. Methods include reacting neutral metal carbonyl compounds with alkylaluminum complexes.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]The present invention claims priority to U.S. provisional patent application No. 62 / 028,993, filed Jul. 25, 2014, the entire contents of which are hereby incorporated by reference.ACKNOWLEDGMENT OF GOVERNMENT SUPPORT[0002]This invention was made with Government support under Grant No. DE-EE0005766, awarded by the Department of Energy. The government has certain rights in the invention.BACKGROUND OF THE INVENTION[0003]Bimetallic complexes containing a cationic metal-centered Lewis acid in combination with an anionic metal carbonyl are highly active catalysts for the ring-expanding carbonylation of strained heterocycles, including epoxides, aziridines, oxetanes and lactones. In particular, such bimetallic catalysts comprising a cationic aluminum complex as a Lewis-acidic component and a carbonyl cobaltate anion are useful for the double carbonylation of epoxides to succinic anhydrides (Rowley et al., J. Am. Chem. Soc., 2007, 129, 4948-4960)...

AI Technical Summary

Benefits of technology

where each of Q, M, Q′, w, d, Ra′, Rb′, Rc′, and Rd′ are as defined above and in the classes and subclasses herein, are characterized in that the catalysts thus formed have little or no contamination with halide and / or alkali metal salts. In certain embodiments, the methods are characterized in that the catalyst formed is essentially free of halide. In certain embodiments, the methods are characterized in that the catalyst composition formed has a halide content less than about 200 ppm. In certain embodiments, the methods are characterized in that the catalyst composition formed has a halide content less than about 150 ppm, less than about 100 ppm, less than about 50 ppm, less than about 40 ppm, less than about 30 ppm, less than about 20 ppm, less than about 10 ppm, less than about 5 ppm, less than about 2 ppm, or less than about 1 ppm. In certain embodiments, the methods are characterized in that the catalyst composition formed is essentially free of alkali metal salts. In certain embodiments, the methods are characterized in that the catalyst composition formed has an alkali metal salt content less than about 200 ppm. In certain embodiments, the methods are characterized in that the catalyst formed has an alkali metal salt content less than about 150 ppm, less than about 100 ppm, less than about 50 ppm, less than about 40 ppm, less than about 30 ppm, less than about 20 ppm, less than about 10 ppm, less than about 5 ppm, less than about 2 ppm, or less than about 1 ppm. It will be appreciated that the amounts of halide or alkali metal salts in this paragraph refer to contaminant impurities or byproducts, not halogen atoms or counterions that are part of the desired catalyst.

Problems solved by technology

Unfortunately, this procedure has features that make its implementation on large scale impractical.

Firstly, the alkali metal salt of the carbonyl cobaltate utilized for the synthesis is not commercially available and must be formed in a separate step (typically from dicobalt octacarbonyl) then isolated and purified prior to use.

Typically, this is done by recrystallizing the air sensitive catalyst which, while practicable at laboratory scale, is problematic at production volumes.

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