Intermolecular Formation of Two C-C Bonds across Olefins Enabled by Boron-Based Relay Strategies.

Smooth handoff in the relay: Vinyl boronates enable the direct addition of nucleophilic and electrophilic or nucleophilic and radical-generating carbon reagents across the double bond with retention of the valuable boronate group. The key to the success of this difficult twofold C-C bond-formation strategy is the initial relay of the nucleophilic addition to boron and the rearrangement of a 1,2-metalate rearrangement, shuttling it to the carbon atom.