Several routes to a complex phosphinate phosphapeptide analogous to the gamma-glutamyl peptide Glu-gamma-Glu have been investigated. Formation of gamma-phosphono glutamate derivatives via addition of a phosphorus-based radical to protected vinylglycine was found to be of limited value because of the elevated temperatures required. Alkylation and conjugate addition reactions of trivalent phosphorus (P(III)) species were investigated. In situ generation of bis-trimethylsilyl esters of phosphinous acids proved to be an effective route to phosphinates of modest structural complexity. However, this chemistry could not be extended to the incorporation of an amino acid moiety at the N-terminal side of the desired phosphinate. A successful synthesis of the target phosphinate phosphapeptide was effected using P(III) chemistry and dehydrohalogenation to yield an alpha,beta-unsaturated phosphinic acid ester, following which conjugate addition of diethylacetamido malonate and acid-mediated hydrolysis afforded the desired phosphinate phosphapeptide. Coupling of the unprotected phosphinate phosphapeptide with two acyl azides derived from folic acid and methotrexate led to the corresponding pteroylphosphapeptides of interest as possible mimics of tetrahedral intermediates in the reaction catalyzed by folylpolyglutamate synthetase.

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We synthesised a series of dissymmetric bistolane derivatives and evaluated their liquid-crystalline (LC) and photoluminescence properties in detail. In measuring LC behaviours, rational structural design based on the dissymmetric molecular structure and electron-density distribution facilitated the production of the LC phase with a wide temperature range (up to 97 °C). In addition, dissymmetric bistolane derivatives were shown to strongly emit blue-photoluminescence in dilute solution and in crystalline states. It was found that dissymmetric bistolanes possess emissive features in even the LC phase and photoluminescence behaviours such as emission intensity and colour were sensitively switched depending on the molecular aggregate structure caused by applying a thermal stimulus.

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The reaction of chlorodifluoromethane with various acetylides derived from the corresponding prop-2-ynylic alcohols proceeds smoothly to afford difluoromethylated compounds in high yields; synthetic applications of the materials are also given.

Incorporation of fluorine atoms into the tolane backbone constructed tight crystal packing structures to suppress molecular motions, which provided dramatic enhancement of photoluminescence efficiency in crystalline state.

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