Palladacyclic Imidazoline–Naphthalene Complexes: Synthesis and Catalytic Performance in Pd(II)-Catalyzed Enantioselective Reactions of Allylic Trichloroacetimidates
作者:Jeffrey S. Cannon、James H. Frederich、Larry E. Overman
DOI:10.1021/jo2025724
日期:2012.2.17
evaluated as catalysts for the rearrangement of prochiral (E)-allylic trichloroacetimidate 19 (eq 2) and the SN2′ allylic substitution of acetic acid with prochiral (Z)-allylic trichloroacetimidate 23. Although these complexes were kinetically poor catalysts for the Overman rearrangement, they were good catalysts for the allylic substitution reaction, providing branched allylic esters in high yield. However
从 2-iodo-1-naphthoic 酸和对映体纯 β-氨基醇三个步骤中,以良好的总收率制备了一个新的空气和湿稳定性对映体纯C , N-钯环(PIN-acac 复合物)。其中三个 PIN 复合物通过单晶 X 射线分析进行了表征。正如预期的那样,PIN-acac 复合物18a和18b的萘和咪唑啉环从平面显着倾斜,并将咪唑啉取代基 R 1和 R 2投射到钯方形平面的相对面上。评估了 15 种 PIN 配合物作为前手性 ( E )-烯丙基三氯乙酰亚胺酯19重排的催化剂(eq 2) 和乙酸与前手性 ( Z )-烯丙基三氯乙酰亚胺23的 S N 2' 烯丙基取代。尽管这些配合物是 Overman 重排的动力学不良催化剂,但它们是烯丙基取代反应的良好催化剂,以高产率提供支链烯丙基酯。然而,对映选择性是低到中等的,并且明显低于使用 COP 家族的钯环配合物实现的选择性。计算研究支持与使用 COP 催