Dual Palladium-Photoredox-Mediated Regioselective Acylation of Carbazoles and Indolines.

We have described a dual palladium-photoredox-catalyzed highly regioselective acylation of carbazoles and indolines using molecular oxygen as the green oxidant. The reaction shows a broad substrate scope and good functional group tolerance. Late-stage functionalization of a carprofen drug derivative, further manipulation of products, and gram-scale synthesis of the acylated products were illustrated to show the versatility of the method.

Photomediated Tandem Sulfonyl Addition-Chemoselective N-Cyclization of -Alkenyl Aryl Ureas: Direct Assembly of Functionalized Dihydroquinazolinones.

Photoredox-mediated tandem addition-chemoselective cyclization of -alkenyl aryl ureas is reported for the synthesis of sulfonyl and activated alkyl-decorated dihydroquinazolinones. By a careful choice of -alkenyl aryl urea starting materials, we achieved chemoselective N-cyclization in the presence of more reactive amidic oxygen. We have demonstrated the scope of the methodology with a variety of sulfonyl chlorides and activated alkyl halides.

Photoredox catalyzed cascade CF addition/chemodivergent annulations of -alkenyl aryl ureas.

Herein, we report a substrate-controlled cascade cyclization of -alkenyl aryl ureas, an ambident nucleophile for constructing functionalized heterocycles such as 2-amino-1,3-benzoxazines and dihydroquinazolinones in a chemodivergent fashion using photoredox catalysis under mild conditions. The versatility of the method has been successfully demonstrated by applying this strategy to a wide range of substrates and for the synthesis of functionalized etifoxine drug derivatives.

Dual palladium-photoredox catalyzed chemoselective C-H arylation of phenylureas.

A highly chemoselective C-H arylation of phenylureas has been accomplished using dual palladium-photoredox catalysis at room temperature without any additives, base or external oxidants. Regioselective C-H arylation of N,N'-diaryl substituted unsymmetrical phenylureas has also been accomplished by a careful choice of aryl groups.