A series of unsymmetrical 2,3-diaryl epoxides were hydrogenated under transfer-hydrogenation conditions using the polyurea-encapsulated palladium catalyst [Pd(0)EnCatTM]. The position of the cleaved C-O bond was determined by ¹H NMR analysis of the ring-opened products derived from the epoxide, in which one of the two benzylic methyne protons is deuterated. The ratio of ring-opened products of the unsymmetrically substituted 2,3-diaryl epoxides was affected by the degree of the steric bulkiness on the aromatic ring.
使用聚
脲包封
钯催化剂 [Pd(0)EnCatTM],在转移加氢条件下氢化了一系列不对称的 2,3-二芳基
环氧化物。通过对
环氧化物生成的开环产物进行¹H NMR 分析,确定了裂解的 C-O 键的位置,其中两个苄基甲基质子中的一个被氚化。非对称取代的 2,3-二芳基
环氧化物开环产物的比例受芳香环上立体丰满度的影响。