Reaction control photochemical reactions templated

Several review articles have dealt with various aspects of cycloaddition reactions. A short review has presented examples to illustrate the use to which tethered alkenes can be put in the synthesis of cyclobutenes. The photochemical (2 + 2)-cycloaddition of enones to ethene has been studied from a theoretical standpoint. A review has highlighted the use of linear templates to control photochemical reactions such as (2 + 2)-photocycloadditions. The stereochemical control of photochemical reactions in clay-intercalated compounds has been discussed. A review has highlighted the interdisciplinary nature of photochemistry. ... 

When chemical reactions are carried out in inclusion complexes, reactions can proceed selectively due to template control effects caused by the host compound. In some cases, reaction occurs only in the inclusion complex, but not in solution, since molecules can be arranged in the appropriate positions for reaction in an inclusion crystal. When an optically active host compound is used, enantiose-lective reactions can be accomplished. For some time we have been studying such selective reactions in inclusion complex crystals in the solid state. However, these reactions have already been published in the book Organic Solid State Reactions [1], In this present chapter, some representative topics and some recent new results of selective thermochemical and photochemical reactions in inclusion crystals are briefly summarized. 

The intramolecular photochemical synthesis of phanes can be apphed to the construction of covalent templates. Moreover, the cyclobutane ring(s) formed by the cycloaddition reaction can act as a stereochemical control forcing the phane conformation to one side similar to a caUper system. Other work has been directed towards the synthesis of receptors and ionophores apphcable to host-guest chemistry. ... 

---