(reagent used as a linker for solid-phase organic synthesis)
Alternate Name: (diisopropylchlorosilyl)polystyrene.
Preparative Methods: lithiated polystyrene can be prepared via direct lithiation of cross-linked polystyrene with (1:1) BuLi and TMEDA at 65 °C in cyclohexane (
Handling, Storage, and Precautions: reagent is water sensitive and cannot be stored for prolonged periods.
Silyl styrene monomers were prepared from p-bromostyrene via lithium-halogen exchange with BuLi followed by quenching with diisopropylchlorosilane (
Subsequent treatment with 1,3-dichloro-5,5-dimethylhydantoin in THF provides the Rasta-(diisopropylchlorosilyl) TEMPO methylpolystyrene resin (
Silyl ether linkers are advantageous for solid-phase organic synthesis due to their ease of formation and cleavage, provided that the synthetic strategy does not require other silyl protecting groups or strongly acidic conditions.4 (Diisopropylchlorosilyl)polystyrene can be used as a silyl ether linker by treatment of an alcohol with the reagent resin in the presence of a base such as pyridine or diisopropylethylamine (
Diisopropylsilyl linkers on polystyrene resins have been used in solid-phase synthesis of oligosaccharides and glycoconjugates via the glycal assembly method (
Diisopropylsilyl linkers are more stable to glycosylation conditions than their diphenyl counterparts (see polymer-bound diphenyl chlorosilane). Rasta-(diisopropylchlorosilyl) TEMPO methyl- polystyrene resins have been demonstrated as viable polymeric supports (
Polymer-bound diphenyl chlorosilane, trityl chloride resin;
Massachusetts Institute of Technology, Cambridge, MA, USA