“Click” post-synthetic modification of metal−organic frameworks for asymmetric aldol catalysis

The reaction of dimethyl 5-(prop-2-ynyloxy)isophthalic acid, meso-alpha, and beta-di (4-pyridyl) glycol with ZnCl2 in a methanol aqueous solution affords MOF Zn−DPPG. The enantiomeric Zn−Fun1 and Zn−Fun2 were obtained through a strategy of in situ click reactions of Zn–DPPG with two opposite chiral adducts. With the l- or d-proline chiral functionality, the two Zn−Funs exhibited remarkable catalytic activities in the relative asymmetric aldol reactions, leading to the formation of opposite enantiomorphs, respectively.