A New Set of Isoreticular, Homochiral Metal-Organic Frameworks with ucp Topology

作者：Sartor Michael; Stein Timo; Hoffmann Frank; Froeba Michael

来源：Chemistry of Materials, 2016, 28(2): 519-528.

DOI：10.1021/acs.chemmater.5b03723

A new isoreticular series of metal-organic frameworks, called UHM-25 (UHM: University of Hamburg Materials), based on the copper paddle wheel motif and a novel set of homochiral linkers has been synthesized. Starting from amino acids available from the chiral pool a synthesis procedure was established that allows a straightforward, multigram scale synthesis of homochiral linkers in 4-5 steps. These linkers carry substituents that have been proven useful in stereoselective organic chemistry, such as the Evans auxiliary or chiral amino alcohols. The resulting MOFs only differ in the chiral moiety provided by the amino acid starting material. The structure of UHM-25 is composed of cuboctahedral cages of Cu-2 paddle wheel motifs connected by the isophthalate moieties of the linker. These cages are linked via the bent backbone of the linker resulting in a primitive cubic arrangement, giving rise to the rare underlying (3,4)-c binodal net ucp. MOFs of the UHM-25 series show surface areas up to S-BET = 1900 m(2)/g. Postsynthetic modification reactions with excellent conversion rates confirmed the accessibility to the chiral groups. Furthermore, UHM-25-Pro bearing a prolinol functionality was used in a self-directed, enantioselective aldol addition of acetaldehyde, demonstrating the potential of the UHM-25 series with regard to heterogeneous, stereoselective catalysis.

• 出版日期2016-1-26