The arylethylamine pharmacophore is conserved across a range of biologically active natural products and pharmaceuticals, particularly in molecules that act on the central nervous system. Herein, we present a photoinduced coppercatalyzed azidoarylation of alkenes at a late stage with arylthianthrenium salts, allowing access to highly functionalized acyclic (hetero)arylethylamine scaffolds that are otherwise difficult to access. A mechanistic study is consistent with a rac-BINAP-Cu I -azide (2) as the photoactive catalytic species. We show the utility of the new method by the expedient synthesis of racemic melphalan in four steps through C−H functionalization.

The metal-free C–H functionalisation is providing environmentally benign, cost-effective, sustainable catalytic systems. Comprehensive developments of various metal-free C–H functionalisation reactions are the focal point of this review.

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Transition metal catalyzed cross-coupling is a versatile tool for the construction of (hetero)biaryl scaffolds. However, the cross-electrophile coupling using abundant (hetero)aryl halides and pseudohalides is still in its infancy. In particular, a robust and general method for the cross-electrophile coupling would allow unparalleled entry into the vast collection of commercially available, structurally-diverse (hetero)aryl halides and pseudohalides as coupling partners. We demonstrate herein a ligand controlled visible light driven monometallic cross-electrophile coupling platform in which the synergistic operation of dual palladium catalytic cycle differentiates the electrophiles based on the bond dissociation enthalpy. This method is mild, robust, selective, and displays unique efficacy towards a wide range of functional groups and challenging heteroaryls, providing access to structurally diverse (hetero)biaryl scaffolds. The power of the transformation has been revealed through the synthesis of (hetero)biaryl core of various pharmaceuticals, and diversification of peptides. The synthesis of more than 54% new (hetero)biaryl core has been demonstrated, allowing access to an expanded chemical space for further exploration in functional materials, drug discovery, and bioconjugation-based therapeutics development. Bypassing the traditional transmetalation step, this technology enables a general strategy for the cross-electrophile coupling of (hetero)aryl halides and pseudohalides.