Visible Light‐Induced Photoredox and Copper‐Catalyzed C−N Cross‐Coupling: A Mechanistic Perspective

Abstract

The formation of C−N bonds is a vital technique in organic synthesis for creating nitrogen‐containing motifs, which has extensive uses in agrochemicals, pharmaceuticals, and natural products. Significant progress has been made in constructing C−N bonds using transition metal catalysis. Nevertheless, utilizing alkyl substrates for the formation of Csp3−N bonds is a notable challenge. Synergistic photoredox and copper catalysis have proven to be a powerful tool to tackle this challenge. The development of this research domain is still in its early stages owing to the chemical and technical complexities of this catalytic process. This review attempts to summarize in‐depth mechanistic understanding of the photoredox/copper dual catalysed C−N coupling reactions taking into consideration of recently reported experimental and theoretical studies.

Cooperative Phosphine-Photoredox Catalysis Enables N–H Activation of Azoles for Intermolecular Olefin Hydroamination

“…12,13 Recently, photo-and electrochemical methods have emerged as a powerful alternative approach toward azole N-alkylation with a diverse set of electrophiles, providing regioselective product formation under mild conditions. [14][15][16] These strategies typically rely on the formation of C-centered radicals or carbocation intermediates from abundant precursors, such as alkyl halides, alkyl carboxylic acids, alkanes, or redox-active esters (Figure 1A). Even with the development of these important synthetic technologies, there is a need for mechanistically distinct approaches that show tolerance across many medicinally relevant heterocycle classes, enable access to products with complementary chemo-and regioselectivity, and engage different classes of feedstocks.…”

Recent advances in C(sp3)–N bond formation via metallaphoto-redox catalysis

“…12 However, there are still very few reviews focusing on surveying the application of metallaphotoredox catalysis in C(sp 3 )–N bond-forming aliphatic amine synthesis. 13 Therefore, in this review, we aim to summarize the recent strategic advances in this burgeoning field of C(sp 3 )–N bond formation via metallaphoto-redox catalysis according to different catalytic modes and reaction types (Fig. 2).…”

Cooperative Phosphine-Photoredox Catalysis Enables N–H Activation of Azoles for Intermolecular Olefin Hydroamination

“…Well-established approaches for N–C­(sp 3 ) bond formation rely on nucleophilic addition of N -centered nucleophiles to an electrophile, such as an alkyl (pseudo)­halide or carbonyl compound . However, the low nucleophilicity of N–H azoles often necessitates harsh reaction conditions that are incompatible with incorporation of secondary or tertiary aliphatic substituents and are not applicable in complex settings. , Recently, photo- and electrochemical methods have emerged as a powerful alternative approach toward azole N -alkylation with a diverse set of electrophiles, providing regioselective product formation under mild conditions. − These strategies typically rely on the formation of C -centered radicals or carbocation intermediates from abundant precursors, such as alkyl halides, alkyl carboxylic acids, alkanes, or redox-active esters (Figure A). Even with the development of these important synthetic technologies, there is a need for mechanistically distinct approaches that show tolerance across many medicinally relevant heterocycle classes, enable access to products with complementary chemo- and regioselectivity, and engage different classes of feedstocks.…”