functionalization of indoles has significantly increased. Particularly, advances in
manganese, iron, cobalt, nickel and copper catalysis have demonstrated the selective C (2)−
H and C (3)− H arylation, alkenylation, alkynylation and alkylation to a greater extent.
Similarly, the C− O and C− N bond‐forming reactions are manifested via direct C− H bond
activation by these earth‐abundant metals. The emergence of 3d metals in selective …