This study reports the synthesis and characterization of cubic boronate ester cages 6, which exhibit unprecedented stability under neutral and slightly acidic conditions. The cages are derived from hexahydroxy tribenzotriquinacenes and phenylene diboronic acids with ortho-t-butyl substituents. The bulky t-Bu groups provide steric shielding, preventing dynamic exchange at the Lewis acidic boron sites under neutral conditions. This steric protection allows the cages to tolerate substantial amounts of water or alcohols in both solution and solid state, making them highly stable under ambient and aqueous conditions. The cages were shown to efficiently encapsulate and release β-carotene dyes upon acid stimulation, and to function as heterogeneous water oxidation catalysts after encapsulating ruthenium complexes. The stability of the cages was demonstrated through various experiments, including NMR, MS, and PXRD analyses, which confirmed the structural integrity of the cages even after prolonged storage in MeOH or water. The cages also exhibited excellent porosity, with a BET surface area of 2534 m²/g. The study highlights the potential of these boronate ester cages for a wide range of applications, including drug delivery, catalysis, and materials science. The results demonstrate that the introduction of t-Bu groups in the ortho-positions of the aromatic boronate ester linkages significantly enhances the stability of the cages under neutral and slightly acidic conditions. This work provides a novel design paradigm for the dynamic covalent construction of highly rigid and directional nanoarchitectures based on boronate esters.This study reports the synthesis and characterization of cubic boronate ester cages 6, which exhibit unprecedented stability under neutral and slightly acidic conditions. The cages are derived from hexahydroxy tribenzotriquinacenes and phenylene diboronic acids with ortho-t-butyl substituents. The bulky t-Bu groups provide steric shielding, preventing dynamic exchange at the Lewis acidic boron sites under neutral conditions. This steric protection allows the cages to tolerate substantial amounts of water or alcohols in both solution and solid state, making them highly stable under ambient and aqueous conditions. The cages were shown to efficiently encapsulate and release β-carotene dyes upon acid stimulation, and to function as heterogeneous water oxidation catalysts after encapsulating ruthenium complexes. The stability of the cages was demonstrated through various experiments, including NMR, MS, and PXRD analyses, which confirmed the structural integrity of the cages even after prolonged storage in MeOH or water. The cages also exhibited excellent porosity, with a BET surface area of 2534 m²/g. The study highlights the potential of these boronate ester cages for a wide range of applications, including drug delivery, catalysis, and materials science. The results demonstrate that the introduction of t-Bu groups in the ortho-positions of the aromatic boronate ester linkages significantly enhances the stability of the cages under neutral and slightly acidic conditions. This work provides a novel design paradigm for the dynamic covalent construction of highly rigid and directional nanoarchitectures based on boronate esters.