Efficient Room-Temperature Oxidation of Hydrocarbons Mediated by Tricopper Cluster Complexes with Different Ligands
作者:Penumaka Nagababu、Suman Maji、Manyam Praveen Kumar、Peter P.-Y. Chen、Steve S.-F. Yu、Sunney I. Chan
DOI:10.1002/adsc.201200474
日期:2012.11.26
hydrogen peroxide concentration when the oxidation of the substrate mediated by the activated tricopper complex is rapid. At low substrate concentrations, the catalytic system exhibits abortive cycling resulting from competing reduction of the activated catalyst by hydrogen peroxide. This behaviour of the system is consistent with activation of the tricopper complex by hydrogen peroxide to generate a strong
已开发了由一系列多齿配体(L)负载的六种[Cu I Cu I Cu I(L)] 1+型三铜簇合物作为氧化催化剂。这些络合物能够介导容易的氧原子转移至烃类底物,例如环己烷,苯和苯乙烯(C 6 H 12,C 6 H 6和C 8 H 8)在室温下被过氧化氢活化。该过程具有高周转频率(TOF)的催化作用,可以中等至高收率将底物有效氧化为相应的醇,醛和酮。催化剂具有鲁棒性,其周转数(TON)仅受用于驱动催化周转的过氧化氢的可用性限制。当由活化的三铜配合物介导的底物的氧化迅速时,TON不受底物浓度的影响,TOF线性依赖于过氧化氢的浓度。在低底物浓度下,催化系统表现出中止循环,这是由于过氧化氢竞争性还原了活化催化剂而导致的。该系统的这种行为与过氧化氢对三铜配合物的活化作用相一致,从而在活化的催化剂和底物之间形成过渡配合物时,生成能够将“氧原子”容易地直接转移至底物的强氧化性中间体。通过改变配体设计也