Turning Diaryl Sulfones into Biaryls

Turning Diaryl Sulfones into Biaryls

Author: ChemistryViews.org

Organosulfur compounds are useful reagents in organic synthesis. Sulfones are particularly interesting due to the leaving group character of sulfonyl. Dialkyl sulfones, for example, can be converted to alkenes via a loss of SO2.

Hideki Yorimitsu and colleagues, Kyoto University, Japan, have developed an intramolecular desulfitative coupling that converts diaryl sulfones to the corresponding biaryls via a catalytic elimination of SO2. The team used a range of aryl 2-quinolyl sulfones (example pictured) as substrates, Ni(cod)2 (cod = 1,5-cyclooctadiene ) as a catalyst, an N-heterocyclic carbene as a ligand, and Mg shavings as a reducing additive.

The desired diaryl products were obtained in moderate to good yields. The proposed catalytic cycle involves the formation of a Ni(0)–NHC complex, which cleaves one C–SO2 bond to give arylnickel(II) sulfinates. SO2 is then eliminated from these intermediates, leading to diarylnickel(II) species. A final reductive elimination gives the desired biaryl compounds. The developed approach can also be used for the conversion of alkenyl aryl sulfones to alkenyl arenes.


 

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