IP Library › Granted Patent US 12691440
Granted Patent B2
US 12691440 · App. 17/790,027 · Granted Jul 28, 2026

Photoredox catalysts and methods of using such catalysts

Inventors: Garret M. Miyake (Fort Collins, CO); Justin P. Cole (Fort Collins, CO); Ryan M. Pearson (Fort Collins, CO); Chern-Hooi Lim (Superior, CO); Max Kudisch (Fort Collins, CO); Dian-Feng Chen (Fort Collins, CO)
Assignees: Colorado State University Research Foundation; New Iridium, Inc.
B01J31/0247B01J31/006B01J35/39C07D209/62
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Quick Facts
Patent No.
US 12691440
App. No.
17/790,027
Granted
Jul 28, 2026
Kind
B2
Abstract

The disclosure relates to photoredox catalysts (PC) and methods for the Birch reductions of aromatic substrates, such as benzene, benzeneoid, and heteroaromatic compounds, using light as the driving force. Certain aspects of the disclosure encompass methods for reduction of aromatic substrates. The method comprises contacting an aromatic substrate with a sacrificial electron donor in the presence of a photoredox catalyst in a solvent, thereby forming a reaction mixture; exposing the reaction mixture to visible or UV light under reaction condition sufficient to reduce the aromatic substrate compound.

Claims (33)

1 . A photoredox catalyst comprising Formula (I) or a salt thereof:

wherein:

A is selected from an optionally substituted C 1 to C 16 alkyl, an optionally substituted aryl, an optionally substituted heteroaryl, a halogen, —CN, —OR 3 , —C(O)R 3 , —C(O)OR 3 , —C(O)NR 4 R 5 , —NO 2 , —NR 4 R 5 , —SR 3 , —S(O)R 3 , —S(O) 2 R 3 , C 1 to C 8 substituted alkyl, C 1 to C 8 unsubstituted alkyl;

R 3 is selected from —H, —NR 4 R 5 , C 1 to C 8 substituted alkyl, or C 1 to C 8 unsubstituted alkyl, substituted aryl, unsubstituted aryl, substituted heteroaryl, or unsubstituted heteroaryl; and

R 4 and R 5 are each independently selected from —H, C 1 to C 8 substituted alkyl, C 1 to C 8 unsubstituted alkyl, substituted aryl, unsubstituted aryl, substituted heteroaryl, or unsubstituted heteroaryl; and

R 2 is selected from an optionally substituted C 1 to C 16 alkyl, an optionally substituted aryl, or an optionally substituted heteroaryl.

2 . The photoredox catalyst of claim 1 , wherein A is selected from:

wherein:

R 1 is selected from —H, halogen, —CN, —OR 3 , —C(O)R 3 , —C(O) OR 3 , —C(O) NR 4 R 5 , —NO 2 , -NR 4 R 5 , —SR 3 , —S(O)R 3 , —S(O) 2R 3 , C 1 to C 8 substituted alkyl, C 1 to C 8 unsubstituted alkyl, substituted aryl, unsubstituted aryl, substituted heteroaryl, or unsubstituted heteroaryl;

R 3 is selected from —H, —NR 4 R 5 , C 1 to C 8 substituted alkyl, or C 1 to C 8 unsubstituted alkyl, substituted aryl, unsubstituted aryl, substituted heteroaryl, or unsubstituted heteroaryl; and

R 4 and R 5 are each independently selected from —H, C 1 to C 8 substituted alkyl, C 1 to C 8 unsubstituted alkyl, substituted aryl, unsubstituted aryl, substituted heteroaryl, or unsubstituted heteroaryl.

3 . The photoredox catalyst of claim 2 ,

wherein:

R 1 is selected from —H, C 1 -C 6 alkyl, C 1 -C 6 haloalkyl, optionally substituted phenyl, —OH, —O(C 1 -C 6 alkyl), —NO 2 , —CN, —C(═O)OH, —C(═O)O(C 1 -C 6 alkyl), —C(═O)O-phenyl, —C(═O)(C 1 -C 6 alkyl), —C(═O)-phenyl, —S(O) 2 NH 2 , —S(O) 2 NH(C 1 -C 6 alkyl), —S(O) 2 N(C 1 -C 6 alkyl)(C 1 -C 6 alkyl), —S(C 1 -C 6 alkyl), —S(O)(C 1 -C 6 alkyl), —S(O) 2 (C 1 -C 6 alkyl), —S(phenyl), —S(O)(phenyl), and —S(O) 2 (phenyl).

4 . The photoredox catalyst of claim 2 ,

wherein:

R 1 is selected from —H, halogen, —CN, —OR 3 , —NR 4 R 5 , C 1 to C 8 substituted alkyl, C 1 to C 8 unsubstituted alkyl, substituted aryl, unsubstituted aryl, substituted heteroaryl, or unsubstituted heteroaryl;

R 2 is selected from C 1 to C 16 substituted or unsubstituted alkyl;

R 3 is selected from —H, C 1 to C 8 substituted alkyl, or C 1 to C 8 unsubstituted alkyl; and

R 4 and R 5 are independently selected from —H, C 1 to C 8 substituted alkyl, or C 1 to C 8 unsubstituted alkyl.

5 . The photoredox catalyst of claim 2 ,

wherein:

R 1 is selected from H, halogen, CN, OR 3 , NR 4 R 5 , C 1 to C 4 substituted alkyl, C 1 to C 4 unsubstituted alkyl, substituted aryl, unsubstituted aryl, substituted heteroaryl, or unsubstituted heteroaryl;

R 2 is selected from C 1 to C 12 substituted or unsubstituted alkyl;

R 3 is selected from H, C 1 to C 4 substituted alkyl, or C 1 to C 4 unsubstituted alkyl; and

R 4 and R 5 are independently selected from H, C 1 to C 4 substituted alkyl, or C 1 to C 4 unsubstituted alkyl.

6 . The photoredox catalyst of claim 2 , wherein:

R 1 is selected from H, fluoride, chloride, bromide, CN, OR 3 , NR 4 R 5 , methyl, ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl, iso-butyl, t-butyl, CCl 3 , CF 3 , phenyl;

R 2 is selected from C 1 to C 8 substituted or unsubstituted alkyl;

R 3 is selected from H, methyl, ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl, iso-butyl, t-butyl; and

R 4 and R 5 are independently selected from H, methyl, ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl, iso-butyl.

7 . The photoredox catalyst of claim 2 , wherein:

R 1 is selected from H, bromide, CN, OR 3 , NR 4 R 5 , CF 3 , phenyl; R 2 is 2-ethylhexyl; and R 3 , R 4 , and R 5 are methyl.