Construction Of Chiral Coordination Polymers And Their Applications In Asymmetric Catalysis

Recently, the design and construction of chiral coordination polymers (CCPs) has been a topical area owing to their intriguing variety of architectures and topologies, as well as potential applications in the aspects of asymmetric catalysis, magnetic materials, nonlinear optical materials, stereoselective separation and so on. With lots of efforts in the assembly of CCPs, chemists have achieved fruitful results. Especially, their applications in asymmetric catalysis have gained considerable interests because they can improve the enantioselectivities of the reactions. The key of asymmetric catalysis is the design and synthesis of the catalysts with high enantioselectivities and activities. Based on this principle, we have synthesized CCPs by use of chiral 1,2-diaminocyclohexane derivatives and researched their applications in the asymmetric Henry reactions. The main contents are as follows:Three chiral ligands (1R,2R)-2,6-edpa, (1S,2S)-2,6-edpa、(1S,2S)-2-cdpa have been synthesized and characterized by’HNMR, ESI-MS, IR spectra. Five CCPs were obtained by use of these ligands and Cu(Ⅱ) salts, and further characterized by single crystal X-Ray diffraction analysis, IR, XRD, TG and CD spectra.The crystal {{Cu(1R,2R)-2-cdpa}·2NO3·2H2O}n(1) in our lab was previous obtained, applied to the diastereoselective Henry reactions. Temperature, solvents, the amount of auxiliary base and the base were screened to obtain the optimum reaction conditions. The catalyst was then generalized to a wide range of aromatic aldehydes with different size and shape, as well as different electronic and steric effects. Then the crystals{Cu3[(1R,2R)-2-cdpa]3(CH3OH)3}·6ClO4·6CH3OH (4)[82]、 {Cu1.5[(1R,2R)-2-cdpa]1.5(4,4’-dipyridyl)}·H2O·3ClO4·HClO4·2H2O (5)[82]、 {{Cu[(1R,2R)-2,6-edpa][H2O]}·2NO3·2H2O}n(6) were used to the asymmetric Henry reactions as the catalysts to obtain considerable yields and moderate enantioselectivities.