<p>The structural diversification of pharmaceutically relevant compounds presents unique challenges to catalytic methodologies that have been developed and optimized on simpler substrates that lack drug-like complexity. Here we report a general strategy for carbon–heteroatom (C–X) bond formation through reactions between a wide range of nucleophiles and nickel-based oxidative addition complexes of drug-like aryl and heteroaryl electrophiles. These organonickel complexes are easily synthesized by oxidative addition of the corresponding electrophiles under electroreductive conditions using an inexpensive nickel precursor. Redox-induced oxidative coupling from these persistent complexes proved challenging, but mechanistic studies guided the development of a simple aerobic oxidation procedure to rapidly form C–X coupled products. Exposure of the organonickel complexes to ambient air forms a high-valent (peroxo)Ni<sup>III</sup>Ar complex intermediate that can undergo substitution with a variety of nitrogen-, oxygen-, sulfur-, carbon-, phosphorus- or halide-based nucleophiles, which are incorporated into the product. The breadth of this methodology was demonstrated by reactions with unreactive electrophiles, such as aryl chlorides, drug-like (hetero)aryl electrophiles and small peptides. Finally, the aerobic chemistry was miniaturized to allow for high-throughput exploration of substrate diversity with an equally complex set of nucleophilic partners.</p><p></p>

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Nickel-mediated aerobic C(sp2)–nucleophile coupling reactions for late-stage diversification of aryl electrophiles

  • Dipankar Das,
  • Long P. Dinh,
  • Ryan E. Smith,
  • Dipannita Kalyani,
  • Christo S. Sevov

摘要

The structural diversification of pharmaceutically relevant compounds presents unique challenges to catalytic methodologies that have been developed and optimized on simpler substrates that lack drug-like complexity. Here we report a general strategy for carbon–heteroatom (C–X) bond formation through reactions between a wide range of nucleophiles and nickel-based oxidative addition complexes of drug-like aryl and heteroaryl electrophiles. These organonickel complexes are easily synthesized by oxidative addition of the corresponding electrophiles under electroreductive conditions using an inexpensive nickel precursor. Redox-induced oxidative coupling from these persistent complexes proved challenging, but mechanistic studies guided the development of a simple aerobic oxidation procedure to rapidly form C–X coupled products. Exposure of the organonickel complexes to ambient air forms a high-valent (peroxo)NiIIIAr complex intermediate that can undergo substitution with a variety of nitrogen-, oxygen-, sulfur-, carbon-, phosphorus- or halide-based nucleophiles, which are incorporated into the product. The breadth of this methodology was demonstrated by reactions with unreactive electrophiles, such as aryl chlorides, drug-like (hetero)aryl electrophiles and small peptides. Finally, the aerobic chemistry was miniaturized to allow for high-throughput exploration of substrate diversity with an equally complex set of nucleophilic partners.