A nickel-catalyzed direct tetra-alkynylation at the B(3,4,5,6) positions of o-carboranes has been developed using a bidentate directing group strategy. This method delivers B(3,4,5,6)-tetra-alkynylated o-carborane derivatives in high yields. By employing a base metal catalyst in an oxidant-free process, this approach offers a more sustainable, cost-effective, and environmentally benign alternative for synthesizing polyalkynylated o-carboranes.
Zhao et al. (Wed,) studied this question.