Asymmetric epoxidation of cis-1-propenylphosphonic acid (CPPA) catalyzed by chiral tungsten(VI) and molybdenum(VI) complexes
作者:Xin-Yan Wang、Hong-Chang Shi、Chuan Sun、Zhi-Guo Zhang
DOI:10.1016/j.tet.2004.08.103
日期:2004.11
In the presence of 5.0 mol% chiral tungsten(VI) and molybdenum(VI) complexes, the catalytic asymmetric epoxidation of cis-1-propenylphosphonic acid (CPPA) with 30% aqueous H2O2 affording (1R,2S)-(−)-(1, 2)-epoxypropyl phosphonic acid (fosfomycin) was first described. The enantioselectivities of the tungsten and molybdenum catalysts depend strongly on the ligands, reaction temperature and solvent. In
在存在5.0 mol%手性钨(VI)和钼(VI)配合物的情况下,顺式-1-丙烯基膦酸(CPPA)与30%的H 2 O 2水溶液进行催化不对称环氧化,得到(1 R,2 S)-首先描述(-)-(1,2)-环氧丙基膦酸(磷霉素)。钨和钼催化剂的对映选择性很大程度上取决于配体,反应温度和溶剂。在0°C下的CH 2 Cl 2中持续72 h,复合MoO 2 [(+)-campy] 2在ee最高为80%的CPPA的100%转化中催化不对称环氧化。当前环氧化的机理可以描述为直接发生在双相H 2 O-非质子体系界面上的氧转移。