Stimuli-Modulated Metal-Organic Framework (MOF) Reactivity toward a Three-Component Coupling Reaction.

Stimuli-responsive heterogeneous catalysis is a powerful concept that unites the possibility for in situ regulation of the reaction parameter space with the enhanced recyclability of solid-state platforms. The presented work reports the first example of a light-responsive heterogeneous catalyst for a three-component coupling reaction that relies on photochromic-molecule-directed modulation of the copper oxidation states in metal-organic frameworks (MOFs) via a stimuli-responsive spiropyran derivative covalently integrated within a host scaffold. Comprehensive spectroscopic analysis, supported by theoretical modeling, establishes the first correlations among isomerization of a photochromic moiety, modulation of metal oxidation states in MOF metal nodes, and the material's overall chemical reactivity in a three-component coupling reaction. Moreover, this work provides the first confirmation that the photophysical performance of integrated spiropyran derivatives is maintained after exposure to selected reaction conditions, leading to material recyclability while preserving its catalytic activity. The developed photochromic MOF-based catalyst promoted the synthesis of 12 different compounds, including commodity chemicals and pharmaceuticals, with near-quantitative yields under mild reaction conditions while maintaining crystallinity and catalytic performance over multiple reaction cycles. Overall, these findings unlock a novel avenue toward noninvasive control of chemical reactivity via on-demand metal oxidation state modulation, establishing a new design principle for adaptive catalytic systems and offering a transformative pathway toward controllable chemical synthesis.