A radical cascade to 2,3-disubstituted indoles proceeding via acylation or trifluoromethylation of ortho-alkynylphenyl isonitriles is presented. In these cascades, two C−C bonds and one C−O bond are formed using an inexpensive oxidant and a catalytic copper or iron salt. The starting isonitriles are easily accessible, and commercially available aldehydes and fluoromethylation reagents serve as reaction partners. Functional group tolerance is high, as documented by the successful preparation of a series of 2,3-disubstituted indoles.

Fluorinated compounds have become important in the fields of agrochemical industry, pharmaceutical chemistry and materials sciences. Accordingly, various methods for their preparation have been developed in the past. Fluorinated compounds can be accessed via conjugation with fluorinated building blocks, via CÀ H fluorination or via selective activation of perfluorinated compounds to give the partially fluorinated congeners. Especially the direct activation of CÀ F bonds, one of the strongest σ-bonds, still remains challenging and new strategies for CÀ F activation are desirable. Herein a method for the photochemical activation of aromatic CÀ F bonds is presented. It is shown that isonitriles selectively insert into aromatic CÀ F bonds while aliphatic CÀ F bonds remain unaffected. Mechanistic studies reveal the reaction to proceed via the indirect excitation of the isonitrile to its triplet state by photoexcited acetophenone at 350 nm. Due to the relatively mild light used, the process shows high functional group tolerance and various compounds of the class of benzimidoyl fluorides are accessible from aryl isonitriles and commercially available perfluorinated arenes.

(–)-Galanthamine as a drug for the treatment of Alzheimer’s disease has attracted synthetic chemists for decades. However, previous total synthetic and biomimetic approaches often use stoichiometric oxidants (metal oxidants or...