ABSTRACT Solid‐state cross‐coupling is a promising synthetic strategy, enabling green processes and access to otherwise unattainable products. To date, avoiding the harsh mechanical force while achieving the synthesis of highly insoluble materials under mild, additive‐free, and solid‐state conditions remains a challenge especially if heterogeneous catalysis is considered. Inspired by the fundamental diffusion dynamics observed in nature, we developed a polymeric palladium‐catalyzed quasi‐solid‐state Suzuki–Miyaura reaction that proceeds without mechanical input; that is, a granular motion of the components results from heat‐induced convection‐driven mass transfer. This approach enabled the synthesis of various polycyclic aromatic hydrocarbons and functional materials in up to 93% yields with Pd loadings as low as 500 mol ppm. Gram‐scale synthesis of dinaphthyl anthracene as a functional material was successfully achieved under the quasi‐solid‐state reaction conditions. Notably, since no mechanical force is applied during the reaction, it is well‐suited to be analyzed in real time, which is a challenge in solid‐state systems. As a result, in‐situ monitoring of the chemical changes of each of the solid reactants allowed the identification and real time monitoring of a boronate intermediate. In addition, direct microscopic visualization revealed changes in morphology and element distributions, proposing a granular motion mechanism for this transformation.
Vrbica et al. (Wed,) studied this question.