Catalysis by Organic Solids. Stereoselective Diels−Alder Reactions Promoted by Microporous Molecular Crystals Having an Extensive Hydrogen-Bonded Network

Anthracenebisresorcinol derivative 1 as an organic
network material shows a novel catalysis in the solid
state for the acrolein−cyclohexadiene Diels−Alder reaction.
The suggested mechanism involves a catalytic cycle
composed of sorption of the reactants in the cavities of
polycrystalline host 1, preorganized intracavity reaction,
and
desorption of the product. The host also promotes stereoselective
intracavity reactions for alkyl acrylates and
cyclohexadiene but, in this case, not in a catalytic manner.
Relevance of the present system as a functional
organic
analog of zeolites is discussed in light of the kinetics of respective
elementary processes and the effects of pulverization
of the catalyst thereupon as well as X-ray crystal
structures.