Nature Communications, Published online: 10 June 2026; doi:10.1038/s41467-026-74372-7 Benzocyclobutenes (BCBs) represent a highly strained, privileged structural motif with significant applications in drug discovery, medicinal chemistry, organic synthesis, polymers and materials science, yet efficient synthetic methods remain limited. Here, the authors report an oxidant-free Au(I)/Au(III)-catalyzed [2 + 2] annulation strategy for the synthesis of BCBs leveraging a unique class of rationally desi