Study on Coordination Behaviour of Manganese Chloride with L-a-Histidine

The reaction thermodynamic and kinetic equations for the non-reversible reactions are established. The enthalpy change of formation reaction of manganese(II) histidine (His) complex in water has been determined by microcalorimetry, using manganese chloride with L-a-histidine at 298.15-323.15 K. The standard enthalpy of formation of Mn(His)₂ ²⁺(aq) has been calculated. On the basis of experimental and calculated results, three thermodynamics parameters (the activation enthalpy, the activation entropy and the activation free energy), the rate constants, along with three kinetic parameters (the apparent activation energies, the pre-exponential constant and the reaction order) are obtained. The results show that the reaction easily takes place over the studied temperature range. The solid complex Mn(His)₂Cl₂·4H₂O was prepared and characterized by IR and TG-DTG. This revised version was published online in August 2006 with corrections to the Cover Date.     

左旋薄荷醇的不对称合成

以4-羟基-2-丁酮和异丙叉丙酮为起始原料,经羟醛缩合、不对称氢化、羰基还原、钌催化氢化等4步反应制得左旋薄荷醇。总产率为33%,非对映体过量de值达到93%。详细探讨了铜催化剂及其用量、手性配体的选择、反应溶剂和时间等因素对胡薄荷烯酮不对称氢化反应的影响。中间体及目标化合物均通过了¹H NMR、¹³C NMR和HRMS等技术手段的分析测定及结构表征。