A Mild and Efficient Method for<i>N</i>‐Arylnucleobase Synthesis<i>via</i>the Cross‐Coupling Reactions of Nucleobases with Arylboronic Acids Catalyzed by Simple Copper Salts
A simple and efficient copper-salt catalyzed N-arylation of nucleobases is reported. In a mixed solvent of MeOH and H2O, the coupling products were obtained in moderate to excellent yields at room temperature within a short time. A variety of substituted N-aryl nucleobases can be prepared through this procedure.
N-Arylation of uracil and its derivatives 2 with diaryliodonium salts 1 was investigated in order to explore a new synthetic methodology associated with N-aryluracil derivatives. In the presence of K2CO3, the copper-catalyzed arylation gave N1,N3-diarylation products with high selectivity and in good yields (Table 2). However, the use of NaOAc as the base in the copper-catalyzed arylation of 6-methyluracil
Ñ尿嘧啶-Arylation及其衍生物2与二芳基碘盐1为了探索与相关联的新的合成方法进行了研究Ñ -aryluracil衍生物。在K 2 CO 3的存在下,铜催化的芳基化反应具有高选择性和高收率的N 1,N 3-二芳基化产物(表2)。但是,使用NaOAc作为碱在铜催化的6-甲基尿嘧啶(2a)的芳基化反应中产生具有高选择性的N 3-芳基化产物,以及铜催化的尿嘧啶的芳基化(2b)或5-甲基尿嘧啶(=胸腺嘧啶; 2c),N 1-芳基化产物是主要产物(表3)。