A recyclable Cu@C2N nano-catalyst applied in the transformation of alkynes: pH switchable access to ketones and 1,3-diynes

We synthesized a reusable heterogeneous Cu@C 2 N catalyst for pH switchable conversion of alkynes to ketones and 1,3-diynes with 92% and 95% yield. The catalyst has a broad substrate scope, and the reaction conditions are environmentally-friendly.