A general and regioselective method for the chlorination of activated arenes has been developed. The transformation uses iron(III) triflimide as a powerful Lewis acid for the activation of N-chlorosuccinimide and the subsequent chlorination of a wide range of anisole, aniline, acetanilide, and phenol derivatives. The reaction was utilized for the late-stage mono- and dichlorination of a range of target compounds such as the natural product nitrofungin, the antibacterial agent chloroxylenol, and the herbicide chloroxynil. The facile nature of this transformation was demonstrated with the development of one-pot, tandem, iron-catalyzed dihalogenation processes allowing highly regioselective formation of different carbon-halogen bonds. The synthetic utility of the resulting dihalogenated aryl compounds as building blocks was established with the synthesis of natural products and pharmaceutically relevant targets.

Amination and amidation of aryl compounds using a transition-metal-catalyzed cross-coupling reaction typically involves prefunctionalization or preoxidation of either partner. In recent years, a new class of transition-metal-catalyzed cross-dehydrogenative coupling reaction has been developed for the direct formation of aryl C–N bonds. This short review highlights the substantial progress made for ortho-C–N bond formation via transition-metal-catalyzed chelation-directed aryl C–H activation and gives an overview of the challenges that remain for directed meta- and para-selective reactions.1 Introduction2 Intramolecular C–N Cross-Dehydrogenative Coupling2.1 Nitrogen Functionality as Both Coupling Partner and Directing Group2.2 Chelating-Group-Directed Intramolecular C–N Bond Formation3 Intermolecular C–N Cross-Dehydrogenative Coupling3.1 ortho-C–N Bond Formation3.1.1 Copper-Catalyzed Reactions3.1.2 Other Transition-Metal-Catalyzed Reactions3.2 meta- and para-C–N Bond Formation4 C–N Cross-Dehydrogenative Coupling of Acidic C–H Bonds5 Conclusions

A mild, efficient and regioselective method for para‐amination of activated arenes has been developed through a combination of iron and copper catalysis. A diverse range of products were obtained from an operationally simple one‐pot, two‐step procedure involving bromination of the aryl substrate with the powerful Lewis acid iron(III) triflimide, followed by a copper(I)‐catalysed N‐arylation reaction. This two‐step dehydrogenative process for the regioselective coupling of aromatic C−H bonds with non‐activated amines was applicable to anisole‐, phenol‐, aniline‐ and acetanilide‐type aryl compounds. Importantly, the arene substrates were used as the limiting reagent and required no protecting‐group manipulations during the transformation.

A diastereoselective synthesis of highly substituted aminobicyclo[4.3.0]nonanes has been attained using a one-pot multi-bond forming process. A four-step synthetic route was developed for the efficient synthesis of a series of C-7 substituted hept-2-en-6-yn-1-ols. These compounds were then investigated as substrates for a one-pot, three-step tandem process involving a palladium(ii)-catalysed Overman rearrangement, a ruthenium(ii)-catalysed ring closing enyne metathesis reaction followed by a hydrogen bond directed Diels-Alder reaction. The optimisation of the one-pot process has allowed the rapid preparation of a library of aminobicyclo[4.3.0]nonanes with significant molecular complexity and up to four stereogenic centres.

A one-pot ortho-amination of activated arenes using sequential iron and copper catalysis has been developed and utilised for the late-stage structural diversification of biologically active 3,4-dihydroquinolin-2-ones.