How can we conduct reactions for insoluble materials?

I am working on metal organic polydehra topic to synthesize new metal-organic cages or other based frameworks. I want to conduct postsynthetic modification for one cage, but the solubility is very poor in most solvents, only methanol can dissolve but it needs large volume.
My question for who in the field of MOFs, COFs, MOPs, and other related chemistries, how can I deal with the problem of insolubility of synthesized materials to conduct postsynthetic reactions? what are the proposed strategies and methods to attain the target modified compound?


Please you can answer based on your experience with reactions for any insoluble materials.


