A homochiral metal–organic porous material for enantioselective separation and catalysis

Abstract

Inorganic zeolites are used for many practical applications that exploit the microporosity intrinsic to their crystal structures. Organic analogues, which are assembled from modular organic building blocks linked through non-covalent interactions, are of interest for similar applications. These range from catalysis, separation and sensor technology to optoelectronics^1,2,3, with enantioselective separation and catalysis being especially important for the chemical and pharmaceutical industries. The modular construction of these analogues allows flexible and rational design, as both the architecture and chemical functionality of the micropores can, in principle, be precisely controlled. Porous organic solids with large voids and high framework stability have been produced^14,15, and investigations into the range of accessible pore functionalities have been initiated^{7,11,12,16,17,18,19,20,21,22,23}. For example, catalytically active organic zeolite analogues are known^13,22,23, as are chiral metal–organic open-framework materials. However, the latter are only available as racemic mixtures^24,25, or lack the degree of framework stability or void space that is required for practical applications^26,27. Here we report the synthesis of a homochiral metal–organic porous material that allows the enantioselective inclusion of metal complexes in its pores and catalyses a transesterification reaction in an enantioselective manner. Our synthesis strategy, which uses enantiopure metal–organic clusters as secondary building blocks¹⁴, should be readily applicable to chemically modified cluster components and thus provide access to a wide range of porous organic materials suitable for enantioselective separation and catalysis.