| abstract |
A new method for producing unsymmetrically substituted fluorenyl compounds, one step of which is the preparation of 2,7-disubstituted fluoren-9-one derivatives via the nucleophilic substitution of a compound of the formula Dwherein A' is selected from the group consisting of -Br, -Cl, -F, -NO2, and -CN; A is selected from the group consisting of -NO2, -CN, -CO2R, -C(O)R, -SO2R, -SO2RF, -C(CN)=C(CN)2 and -CH=C(CN)2; RF is -CpF2p+1, p=from about 0 to about 10; R is an straight, branched or cyclic aliphatic alkyl group having about 1 to 10 carbon atoms, or an aromatic group such as phenyl or naphthyl; andis a carbonyl or a protected carbonyl such as a ketal or thio-ketal such aswherein R' is -CrH2r+1; R'' is -(CH2)r-; and r is independently 2 or 3, with a nucleophilic reagent in the presence of an aprotic solvent. These unsymmetrically substituted fluorenyl compounds can be used as building blocks for making high glass transition temperature polymers for nonlinear optical applications. |