Room-Temperature and Transition-Metal-Free Intramolecular α-Arylation of Ketones: A Mild Access to Tetracyclic Indoles and 7-Azaindoles.

A novel approach for the synthesis of tetracyclic indoles and 7-azaindoles is reported. The strategy involves four steps, with a fast rt intramolecular α-arylation of ketones as key step. The reaction was inspected synthetically to achieve the synthesis of 11 novel tetracyclic structures with moderate to very good yields (39-85%). Theoretical combined with experimental studies led us to propose a probable polar mechanism (concerted SNAr).

Access to cyclic gem-difluoroacyl scaffolds via electrochemical and visible light photocatalytic radical tandem cyclization of heteroaryl chlorodifluoromethyl ketones.

A variety of unprecedented scaffolds containing a difluoroacyl moiety were obtained in moderate to good yields, with excellent diastereoselectivity, via electrochemical or photochemical activation of difluoroacyl heteroaryles with a series of olefinic substrates.