Organometallic gold(III) and gold(I) complexes as catalysts for the 1,3-dipolar cycloaddition to nitrones: synthesis of novel gold–nitrone derivatives
作者:Ana Adé、Elena Cerrada、Marı́a Contel、Mariano Laguna、Pedro Merino、Tomás Tejero
DOI:10.1016/j.jorganchem.2004.03.001
日期:2004.5
anionic salts mediate the 1,3-dipolar cycloaddition of N-benzyl-C(2-pyridyl)nitrone (2-PyBN) (1) and methyl acrylate (2) (gold 5–10 mol% with respect to the nitrone) decreasing the reaction time and favouring the formation of the exo (cis) isomer. The best catalyst found was Na[AuCl4] (7) able to perform the addition reaction in 56 h (instead of the 96 h required for the control experiment) and giving
金(III)和金(I)阴离子盐介导N-苄基-C(2-吡啶基)硝酮(2-PyBN)(1)和丙烯酸甲酯(2)(5-10金)的1,3-偶极环加成相对于硝酮的摩尔百分数)减少反应时间并有利于外型(顺式)异构体的形成。发现的最佳催化剂是Na [AuCl 4 ](7),它能够在56小时内(而不是对照实验所需的96小时)进行加成反应,并且异构体之间的内/外关系为44/56(相对)至73/27,空白反应)。几种有机金属金配合物与五氟苯基(C 6 F 5)或1(2,4,6-(CH 3)3 C 6 H 2)。在某些情况下,活性与用无机盐获得的活性非常相似。为了确定环加成反应中可能的金属中间体,新型金(III)和金(I)硝酮衍生物,例如[Au(C 6 F 5)Cl 2(2-PyBN)](21),[Au(制备并表征了C 6 F 5)2 Cl(2-PyBN)](22)和[Au(C 6 F 5)(2-PyBN)](23)。[AuCl