Versatile and robust C–C activation by chelation-assisted manganese catalysis

C–H activation has been recognized as an increasingly viable tool in molecular sciences, but organometallic C–C activation is scarce, and limited to precious and toxic metal catalysts. Herein, we disclose versatile C–C activations by a robust base-metal catalyst in water. Thus, an inexpensive manganese(i) catalyst enabled C–C functionalizations with excellent levels of chemo- and position-selectivities, setting the stage for versatile C–C allylations, C–C alkenylations and C–C alkylations in water. The manganese(i) catalyst outperformed commonly used copper, iron, palladium, rhodium and ruthenium complexes, and the C–C activations occurred on steroid and amino acid motifs. Detailed kinetic and computational studies provided strong support for a kinetically relevant C–C manganesation. Unlike the more common C–H functionalization, methods for the functionalization of C–C bonds are scarce. Here, Ackermann and co-workers show that an inexpensive manganese catalyst is capable of selectively activating C–C bonds for alkylations, alkenylations, and allylations in water.