Nickel Metallaphotoredox Buchwald–Hartwig Amination Reactions: A Perspective on Irradiation Light Wavelength

Abstract

AbstractThe construction of C−N bonds is considered one of the most useful reactions in synthetic chemistry due to their widespread presence in pharmaceuticals, natural products, etc. Pd‐catalyzed Buchwald–Hartwig amination (BHA) has provided the most efficient method to form (hetero)aryl amines but it required strong base and sophisticated ligands. In comparison, the combination of photocatalysis and nickel chemistry has revolutionized catalytic strategies and is emerging as a quintessence to realize BHA, termed as Ni‐metallaphotoredox BHA. To pursue a universal protocol, diverse photocatalysts were designed and employed in Ni‐metallaphotoredox BHA, and smoothly promoted C−N bond formations under irradiation of light from ultraviolet to red light, respectively. Note that the matching of photocatalyst and light was critical for success. Therefore, this review mainly focuses on the discussion of Ni‐metallaphotoredox BHA according to the irradiation light's wavelength, covering ultraviolet, purple, blue, red, and white light as well as solar light. We try to find a clue in the relationship of structure‐photophysical behaviors of photocatalysts under the same or different irradiation light. At last, current limitations and potential trends for advancing Ni‐metallaphotoredox BHA are highlighted. We deem that it could encourage chemists to continue designing suitable photocatalyst for C−N bond formations under sunlight mimicking plants’ photosynthesis.