Liquid Crystal Control of uni-to multi-molecular Thermal Reactions

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The aim of this research is to establish the new methodology for highly orientation-regulated reaction system using liquid crystal as medium, with regularity and fluidity. The following typical reactions have tried with a variety of liquid crystal medium :(1)Intramolecular [4+2] cycloaddition (unimolecular reaction) : Intramolecular uncatalyzed thermal cycloaddition reaction of trans-4-cyclohexylcyclohexyl decatrienoic acid esters in smectic liquid crystalline solvents such as bis(4-pentyloxyphenyl)trans-1,4-cyclohexanedicarboxylate (BPCD) was found to give bicyclic cycloadducts with extremely high diastereoselectivity and chemical yields, contrary to the poor results with isotropic medium such as 4-pentyloxyphenyl cyclohexanecarboxylate (PCC) and mesitylene.(2)Intermolecular [4+2] cycloaddition (bimolecular reaction) : Moderate stereoselectivities and reaction accerelation effect were observed for intermolecular cycloaddition with pyrroles and allene diesters in smectic medium.(3)Mitsunobu Reaction (tetramolecular reaction) : Unusual retention of the configuration of hydroxyl group of trans-4-substituted cyclohexanol by Mitsunobu reaction was observed in smectic medium, contrary to the usual result (inversion of configuration) in isotropic medium.