Reactions in cavities can adopt quite different characteristics from those in solvents. Thus first example of the catalysis of the Diels-Alder reaction inside an organic scaffold was reported by Endo, Koike, Sawaki, Hayashida, Masuda, and Aoyama, where the reaction shown below is speeded up very greatly in the presence of a crystalline lattice of the anthracene derivative shown below.
- K. Endo, T. Koike, T. Sawaki, O. Hayashida, H. Masuda, and Y. Aoyama, "Catalysis by Organic Solids. Stereoselective Diels−Alder Reactions Promoted by Microporous Molecular Crystals Having an Extensive Hydrogen-Bonded Network", Journal of the American Chemical Society, vol. 119, pp. 4117-4122, 1997. http://dx.doi.org/10.1021/ja964198s