No abstract

Autoxidation of the phosphonate carbanions derived from 9-phosphono-10-hydroacridanes provided chemiluminescence ascribed to the excited acridone anion. The intramolecular CIEEL (chemically initiated electron exchange luminescence) mechanism can be applied to this chemiluminescence because of the much higher emission efficiency compared to that of 9-phosphono-10-methylacridanes. The effect of the phosphonate substituents on the emission efficiency and especially on the rates of the chemiluminescence decay can be interpreted to originate from the valence deviation of the phosphorus atoms, which is connected with the substituent effect on the geometrical selectivity in the olefination reaction of the phosphonate carbanions. The enhanced chemiluminescence in the presence of the fluorophores was also detected in autoxidation of the carbanions of diethyl diphenylmethylphosphonate and fluorenylphosphonate. Although the evidence is circumstantial, these results strongly support the belief that phospha-1,2-dioxetane is the most likely high-energy intermediate generating the excited molecules.

2001alkenes alkenes (benzene compounds) Q 0083 -097The Horner-Wadsworth-Emmons Reaction of Mixed Phosphonoacetates and Aromatic Aldehydes: Geometrical Selectivity and Computational Investigation.-The effect of the electronic nature of the phosphonate substituents on the geometrical selectivity in the Horner-Wadsworth-Emmons reaction is investigated. The reaction with aromatic aldehydes shows gradual change in Z-selectivity according to the electronwithdrawing ability of the phosphonoacetate substituents. There is a good correlation between the observed selectivities and 31 P chemical shifts of the phosphonoacetates. In addition, the effect of reaction conditions (base, additive) on the ratio of Z-and E-cinnamates is reported. -(MOTOYOSHIYA, JIRO;