| 摘要 |
Calcium-substituted polymeric reagents are provided. These reagents can be prepared via the oxidative addition of a soluble highly reactive calcium species to organic and inorganic polymers containing alkyl, aryl, or alkylaryl pendent groups substituted with halide atoms, cyanide molecules, 1,3-dienes, or any conjugated polyunsaturated system. Preferably, the polymer is a cross-linked p-bromopolystyrene, p-chloropolystyrene, p-fluoropolystyrene, or chloromethylated polystyrene. Preferably, the soluble highly reactive calcium species is prepared from the reduction of Ca(II) salts with an alkali metal arene, such as lithium biphenylide. These calcium-substituted polymeric reagents react with a variety of electrophiles to yield functionalized polymers. Reaction with Cu(I) salts yields calcium-substituted polymeric cuprate reagents, which can react, for example, with acid chlorides to form ketones, alkyl halides containing functionality, and undergo 1,4-conjugate addition with alpha , beta -unsaturated ketones, aldehydes, esters, and amides. Bifunctionalization of the polymer can be achieved by the addition of highly reactive calcium to a functionalized polymer containing a halogen. Polymers can be cross-coupled with dyes, UV stabilizers, biologically active substrates, molecules that impart specifically desired characteristics, among other desirable functional groups.
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