Selective hydroboration of terminal alkynes catalyzed by heterometallic clusters with uranium–metal triple bonds

Due to their fascinating structures and heterometallic synergistic effects in catalysis, heterometallic clusters with metal–metal (M–M) bonds have attracted the interest of chemists for decades. However, understanding of the chemistry of M–M bonds that involve f-block elements, such as uranium, is significantly less developed compared with that of the d-block transition metals, and catalysis by heterometallic clusters with U–M bonds has not been realized to date. Here, we report a set of heterometallic clusters that feature U≡M (M = Fe, Co) triple bonds. The cluster with two U≡Co triple bonds exhibits excellent catalytic activity for the hydroboration of alkynes under mild conditions, producing α-vinylboronates with good yields and regioselectivity. These heterometallic clusters represent the rare structurally authenticated example of multiple bonding between f-block elements and transition metals. Theoretical studies reveal high bond orders (up to 2.93) and a significant degree of covalency in these U≡M triple bonds.