Stabilizing unconventional coordination environments in extended solids remains challenging, particularly for late transition metals such as gold (Au) with limited valence flexibility. Here, we report that a site-selective framework enables the formation of octahedral Au-S coordination in layered ${\mathrm{AuBS}}_3$, a structure related to quasi-$1T$ transition-metal dichalcogenides. Under compression, electron-deficient ${\mathrm{B}}_2{\mathrm{S}}_6$ units constrain the sulfur sublattice and modify the local ligand field, driving Au into an octahedral coordination environment. Electronic structure analysis shows that this framework lowers the energy of Au–S bonding states through overlap between S $3s/3p$ orbitals and Au $6s/6p$ as well as bonding $5d$ ($5d_{yz}$ and $5d_{xz}$) states, while leaving the remaining Au $5d$ ($5d_{xy}, 5d_{x^2\text{−}{y}^2}$, and $5d_{z^2}$) orbitals to largely retain their nonbonding character, thereby stabilizing the octahedral configuration beyond conventional valence constraints. As a consequence, ${\mathrm{AuBS}}_3$ exhibits intrinsic superconductivity, primarily originating from the strong electron-phonon coupling between Au–S antibonding electrons and low-frequency vibrations associated with Au–S bonds. These results highlight the role of framework-constrained bonding reconstruction in stabilizing unconventional coordination geometries and provide insight into the design of transition-metal chalcogenides under pressure.

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• Chemical bonding
• Crystal structure
• Pressure effects
• Superconductivity
• Layered crystals
• Density functional calculations