Optically active imidazole derivatives featuring an α-amino acid motif substituted at the 2-position can be prepared in moderate to good yields by Negishi as well as Suzuki-Miyaura cross-couplings as the key synthetic steps. The reaction sequence involves N-protection (ethoxymethylation), whereby both generated regioisomers could be separated by column chromatography, and selective 2-lithiation. Subsequent transmetalation to zinc or an iodine quench affords reactants suitable for Pd-catalyzed Negishi and Suzuki-Miyaura reactions with (hetero)aromatics.
以 2 位取代的δ-
氨基酸为特征的光学活性
咪唑衍
生物,可以通过根岸和铃木-宫浦交叉耦合作为关键合成步骤,以中等到良好的收率制备出来。反应顺序包括 N-保护(乙氧基甲基化)和选择性 2-
硫化。随后进行反
金属
锌或
碘淬火,得到的反应物适用于 Pd 催化的 Negishi 和 Suzuki-Miyaura 与(杂)
芳烃的反应。