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DOI: 10.1055/s-2005-869880
Cooperative Catalysis by General Acid and Base Bifunctionalized Mesoporous Silica Nanospheres
Contributor(s): Yasuhiro Uozumi, Masahiro KimuraIowa State University, USA
Cooperative Catalysis by General Acid and Base Bifunctionalized Mesoporous Silica Nanospheres
Angew. Chem. Int. Ed. 2005, 44: 1826-1830
Publication History
Publication Date:
20 July 2005 (online)
Key words
cooperative phenomena - heterogeneous catalysis - mesoporous materials - organic-inorganic hybrid composites - silicon
Significance
Bifunctinalized mesoporous silica nanospheres (MSNs) having a general acid, the ureidopropyl group (UDP), and a general base, 3-[2-(2-aminoethylamino)ethylamino]propyl group (AEP), were synthesized. The AEP/UDP-MSNs catalyzed the carbonyl activation reactions, aldol reaction, Henry reaction, and cyanosilylation with high TONs up to 22.6, 125.0, and 276.1, respectively.
Comment
Recently, a new synthetic method to functionalize mesoporous silica with multiple organic groups was reported from the author’s group, by which the loading of functional groups, particle size, and shape of the mesoporous silicas could be controlled (for example, see: S. Huh, J. W. Wiench, J.-C. Yoo, M. Pruski, V. S.-Y. Lin Chem. Mater. 2003, 15, 4247-4256). The authors discussed that the AEP and the UDP activate both the nucleophile and the electrophile at the same time, cooperatively.