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

An approach for the assembly of phenanthrone derivatives with all carbon quaternary centres has been developed using visible light-promoted tandem sulfonylation/intramolecular-arylation. The synthetic strategy has been extended to include thiotrifluoromethyl and thiocyanato radicals under oxidative conditions. The scalability and versatility of the synthesis were also demonstrated.