Diethanolaminomethyl polystyrene

30 Solid-phase immobilization and derivatization of boronic acids using N,N-diethanolaminomethyl polystyrene (DEAM-PS, 107). 

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Phase-switching strategy was applied to the multistep synthesis of isoxazolines 45-47. The approach exploits the boronic acid functionality as a phase-tag which can be easily immobilized on diethanolaminomethyl polystyrene (DEAM-PS) resin and then released by treatment with wet THF. Each reaction step was carried out in solution and the products were purified by addition of the scavenging resin, followed by filtration, washing of the supported material, hydrolytic release and evaporation. Finally, the boronic acid could be used to introduce additional substituents on the molecule. For example, 46 was converted into the biaryl-containing isoxazoline 47 by a Suzuki cross-coupling reaction <07JCO193>. 

Gravel et al. [353] described a structural diversification of boronic acids attached to a solid phase via a boronic acid-selective support link (438) (see Section 4.2.1). The authors used N,N-diethanolaminomethyl polystyrene (DEAM-PS) for this task. 

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