Synthesis of functionalized phenylalanine derivatives by ring opening reactions of 3-arylaziridine-2-carboxylic esters
作者:Johan Legters、Lambertus Thijs、Binne Zwanenburg
DOI:10.1002/recl.19921110102
日期:——
respectively, due to the electron-releasing properties of the p-methoxy group. Only C3 attack was observed. Under the same conditions, 1b and 1c gave a clean SN2-type ring opening, leading to diastereomerically pure products 4b, 4c, 6b and 6c. Reaction of 1b with acetic acid gave 7 in an SN2-type ring opening at C3, followed by an ON acyl shift. Treatment of enantiopure (+ )-(2S,3R)-1b with benzenethiol
描述了3-芳基氮丙啶-2-羧酸酯与各种亲核试剂的开环反应。选择外消旋的3-(4-甲氧基苯基)-,3-苯基-和3-(4-硝基苯基)氮丙啶-2-羧酸甲酯(分别为1a,1b和1c)作为底物。在不存在酸的情况下,没有开环发生。用乙醚氯化氢处理时,1a给出非对映异构体2a的混合物,而1b和1c分别给出区域异构体2b / 3b和2c / 3c的混合物。三氟化硼醚化物催化的1a反应由于对甲氧基的电子释放特性,用苯硫醇和吲哚与苯并噻吩还分别形成非对映体开环产物4a和6a。仅观察到C3攻击。在相同条件下,1b和1c产生干净的S N 2型开环,得到非对映异构纯产物4b,4c,6b和6c。1b与乙酸反应,在C3处的S N 2型开环中得到7 ,然后酰基转移为ON。对映体(+)-(2S,3R)-1b的治疗用苯硫醇,吲哚和乙酸与苯甲酸反应,得到相应的对映体纯的β-官能化的α-氨基酸衍生物。的官能1b中在氮气强烈增加的反应性:N-