Synthesis Of Supported Bifunctional (1R,2R)-(-)-1,2-diaminocy-Clohexane Catalysts And Their Applications Inasymmetric Catalysis

In this paper, the supported bifunctional (1R,2R)-(-)-1,2-diaminocyclohexane catalysts, which could be recycled and reused, were prepared by the following steps: substitution reaction of halogenerated hydrocarbon containing ethyl phosphonate and amine with phthalic anhydride-protected one of amino groupes, hydrolysis of ethyl phosphonate and precipitaion with inorganic salt.The catalysts were applied in the various asymmetric catalytic reactions such as anhydride hydrolysis, Morita-Baylis-Hillman reaction, Michael addition and henry reaction. Unfortunately, the racemic products in anhydride hydrolysis reaction could not be isolated by HPLC and given up. The products in asymmetric Morita-Baylis-Hillman reaction with35.3-68.4%yields were found to be no enantioselectivity. In asymmetric Michael addition, the yields and enantioselectivities of nitrostyrolene and dimethyl malonate are not satisfactory. Meanwhile, the good yield in the reaction of chalcone with dimethyl malonate was obtained. Similarly, it had no enantioselectivity. After the catalyst reacted with copper to afford its corresponding complex, the good yields (78.3-86.5%) were obtained in Henry reaction, but the%ee was only13.3-37.5%.Based on the catalytic results of the model reactions, the catalyst was found to be ineffective in enantioselectivity, which maigt be resulted from one of tertiary amines remote to chiral center.