Microwave-assisted N,N-dialkylation of amine-functionalized periodic mesoporous phenylene-silica: An easy and fast way to design materials

- Microwave-assisted functionalization of the walls of periodic mesoporous organosilicas.
- Only two cycles are required to dialkylate NH2-PMO.
- Both meso- and molecular-scale periodicities are preserved.
- (NCCH2CH2)2-N-PMO paves the way for design new functional materials.

N,N-dialkylation reaction of mesoporous aniline-silica is successfully achieved with nearly total conversion of the amine-phenylene periodic mesoporous organosilica (NH2-PMO) to the N,N-dialkylated amine material. Microwave-assisted dialkylation was optimized. Two cycles are required to promote the reaction of 2-bromopropane with the NH2-PMO and obtain the (iPr)2-N-PMO material, with preservation of both meso- and molecular-orders. A similar procedure, using 3-chloropropionitrile as alkylation agent in the same condition parameters, was used to obtain the (NCCH2CH2)2-N-PMO material, also maintaining both meso- and molecular-scale periodicities. This material opens an avenue for the preparation of new functional materials by conversion of the nitrile group into amines, carboxylic acids, amino acids and chiral groups, according to the desired application, by subtle modifications in the synthetic methodology.

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