In this work, a new method of synthesis of functionalized materials <i>via</i> surface Suzuki coupling was developed. As starting materials, mesoporous 3-(mercapto)propyl- and dimethylsiloxy-functionalized silica gel were used. On the first step, surface hydrosilylation and hydrothiolation of the alkene group of 4-vinylphenylboronic acid were used for its immobilization on the silica surface. The hydrothiolation catalyzed by AIBN demonstrated better effectiveness and resulted in higher density of surface boronic acid groups. In contrast, hydrosilylation products were unstable in reaction conditions and decomposed with time. Then immobilized phenylboronic acid reacted with aromatic halides in the presence of palladium acetate and cesium carbonate in DMF. The following halides were used in the synthesis: bromobenzene, iodobenzene, 5-bromo-1-indanone, 4-iodoanisole, (4-chlorophenyl)acetic acid,  4-iodobenzoic acid. Obtained functionalized materials were also mesoporous although their surface area decreased after immobilization. Degree of immobilization of organic halides was calculated from increase of carbon contents after the reaction, and for most of halides varied between 25 and 67%. Only 5-bromo-1-indanone was almost unreactive at the reaction conditions. Conversion of surface boronic acid groups with iodobenzene was higher than with bromobenzene. Electrodonating methoxy group strongly reduced degree of immobilization of iodoanisole. The method can be used for the preparation of various functionalized catalysts, adsorbents and composite materials.

Modification of silica surface by Suzuki coupling

2019 Spring National Meeting

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