Visible-Light Photoredox-Catalyzed C–O Bond Cleavage of Diaryl Ethers by Acridinium Photocatalysts at Room Temperature
We have developed visible-light photoredox-catalyzed C–O bond cleavage of diaryl ethers by an acidolysis with an aryl car-boxylic acid and a following one-pot hydrolysis. Two phenols are obtained from a diaryl ether at room temperature. The aryl carboxylic acid used for the acidolysis can be recovered. The key to success of the acidolysis is merging visible-light photore-dox catalysis with a new acridinium photocatalyst and Lewic acid catalysis with Cu(TMHD)2. Preliminary mechanistic studies indicate that the catalytic cycle occurs via a rare selective electrophilic attack of the generated aryl carboxylic radical on the electron-rich aryl ring of diphenyl ether. This transformation is applied to a gram-scale reaction and the model of 4-O-5 lignin linkages.
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SI
Posted 07 Aug, 2020
Visible-Light Photoredox-Catalyzed C–O Bond Cleavage of Diaryl Ethers by Acridinium Photocatalysts at Room Temperature
Posted 07 Aug, 2020
We have developed visible-light photoredox-catalyzed C–O bond cleavage of diaryl ethers by an acidolysis with an aryl car-boxylic acid and a following one-pot hydrolysis. Two phenols are obtained from a diaryl ether at room temperature. The aryl carboxylic acid used for the acidolysis can be recovered. The key to success of the acidolysis is merging visible-light photore-dox catalysis with a new acridinium photocatalyst and Lewic acid catalysis with Cu(TMHD)2. Preliminary mechanistic studies indicate that the catalytic cycle occurs via a rare selective electrophilic attack of the generated aryl carboxylic radical on the electron-rich aryl ring of diphenyl ether. This transformation is applied to a gram-scale reaction and the model of 4-O-5 lignin linkages.
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8