Radical-mediated sulfonylative/thiolative cyclization of biaryl enones to phenanthrone derivatives

An approach for the assembly of phenanthrone derivatives bearing all carbon quaternary centres has been developed through visible light-promoted tandem sulfonylation/intramolecular-arylation of biaryl enones with sulfonyl chlorides. A series of sulfonylated 10,10-dialkylphenanthrones were obtained in good yields. In addition, the approach has been extended to thiotrifluoromethyl (SCF3) and thiocyanato (SCN) radicals to obtain the corresponding phenanthrones under oxidative conditions. The synthetic utility was also illustrated by the scalability and further transformations of the product. The synthesis of phenanthrone derivatives bearing all carbon quaternary centers has been disclosed, involving tandem sulfonylation or thiolation/intramolecular-arylation of biaryl enones with S-radicals.

Automated summary

A method for the synthesis of phenanthrone derivatives with all carbon quaternary centers has been developed using a visible light-promoted tandem sulfonylation/intramolecular-arylation reaction. This approach yielded a series of sulfonated 10,10-dialkylphenanthrones in good yields. The utility of this method was further demonstrated through scalability and additional transformations of the obtained products.