Compositions and methods for visible-light-controlled ruthenium-catalyzed olefin metathesis

Inventors

Rovis, Tomislav • Theunissen, Cedric

Assignees

Columbia University in the City of New York

Abstract

The present disclosure provides compositions and methods for metathesizing a first alkenyl or alkynyl group with a second alkenyl or alkynyl group, the composition comprising a ruthenium metathesis catalyst and a photoredox catalyst that is activated by visible light.

Core Innovation

The invention provides compositions and methods for metathesizing a first alkenyl or alkynyl group with a second alkenyl or alkynyl group, the composition comprising a ruthenium metathesis catalyst and a photoredox catalyst that is activated by visible light. The metathesis described herein is performed using a ruthenium metathesis catalyst and a photoredox catalyst that is activated by visible light, where "visible light" refers to light that has a wavelength of about 350 nm to about 750 nm. In some embodiments the disclosure provides the use of a latent ruthenium metathesis catalyst bearing two poorly dissociable carbene ligands that is not active for metathesis at ambient temperature without external activation.

The disclosure provides methods of spatially controlling a metathesis comprising forming a mixture of a ruthenium metathesis catalyst, a photoredox catalyst, and one or more compounds susceptible to metathesis; and applying visible light to one or more regions of the mixture so as to give rise to one or more metathesized regions and one or more unmetathesized regions. The visible light can be applied using a high resolution light source or by covering at least one unmetathesized region with a photomask, and the substrate can be functionalized with the one or more compounds susceptible to metathesis. The methods encompass ring-closing metathesis, cross-metathesis, ring-opening metathesis polymerization, and photolithographic olefin metathesis polymerization as metathesis types.

The disclosure describes activation by the photoredox catalyst where energy or electron transfer from/to the excited state of the photocatalyst induces ligand dissociation from the latent metathesis catalyst, generating the active species that promotes ROMP and related reactions; turning the light off leads to re-coordination of the carbene ligand onto the ruthenium catalyst and is thought to shut down metathesis. The disclosure describes that photoredox catalysts that are highly oxidizing contribute to the ease of metathesis and provides examples of photoredox catalysts and bis(NHC)-ruthenium complexes. As a result, the methods are presented as permitting control of initiation and termination of ROMP and enabling temporal and spatial control over product formation.

Claims Coverage

Two independent claims were identified in the patent.

The independent claims cover (1) compositions for metathesizing alkenyl/alkynyl groups that comprise specific bis(NHC)-ruthenium catalysts and (2) a method of performing chemical metathesis by applying visible light to such a composition in the presence of a photoredox catalyst activated by visible light.

Stated Advantages

Documented Applications