Mn-I/Ag-I Relay Catalysis: Traceless Diazo-Assisted C(sp(2))-H/C(sp(3))-H Coupling to beta-(Hetero)Aryl/Alkenyl Ketones

An unprecedented Mn-I/Ag-I-relay-catalyzed C(sp(2))-H/C(sp(3))-H coupling of (vinyl)arenes with alpha-diazoketones is reported, wherein the diazo group was exploited as a traceless auxiliary for control of regioselectivity. Challenging beta-(hetero)aryl/alkenyl ketones were obtained through this operationally simple approach. The cascade process merges denitrogenation, carbene rearrangement, C-H activation, and hydroarylation/hydroalkenylation. The robustness of this method was demonstrated at preparative scale and applied to late-stage diversification of natural products.