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Cesium Carbonate-Catalyzed Oxidation of Substituted Phenylsilanes for the Efficient Synthesis of Polyhedral Oligomeric Silsesquioxanes

Yuefeng Li, Chunming Cui

Inorg Chem. 2018 Nov 5;57(21):13477-13485.

PMID: 30351062

Abstract:

Cesium carbonate-catalyzed oxidation of substituted phenylsilanes (ArSiH3) in N, N-dimethylformamide (DMF) at room temperature for the efficient synthesis of polyhedral oligomeric silsesquioxanes (POSS) was described. This protocol allowed the rapid and selective access to several types of new POSS cages in modest to good yields under nonaqueous conditions. Depending on the bulkiness of the substituents on the phenyl rings, hexa- (T6), octa- (T8), and dodecaphenylsilsesquioxanes (T12) can be selectively obtained. With the more bulky 2-(2',4',6'-trimethylphenyl)phenyl group, the cyclic tetrasiloxane (D4) bearing four hydroxyl groups was isolated. Mechanism studies disclosed that the initial step involved the Cs2CO3-catalyzed hydrosilylation of DMF with a hydrosilane to generate a siloxymethylamine intermediate followed by the dehydrocarbonative cross-coupling of the hydrosilane with the siloxymethylamine.

Chemicals Related in the Paper:

Catalog Number Product Name Structure CAS Number Price
AP534178 Cesium carbonate Cesium carbonate 534-17-8 Price
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