Mechanism of Methoxide Ion Substitution in the <i>Z</i> and <i>E</i> Isomers of <i>O</i>-Methylbenzohydroximoyl Halides
作者:James E. Johnson、Debra D. Dolliver、Lonchun Yu、Diana C. Canseco、Michael A. McAllister、Jeffrey E. Rowe
DOI:10.1021/jo030299e
日期:2004.4.1
isomers of O-methylbenzohydroximoyl halides [1Z and 1E, ArC(X)NOCH3] with sodium methoxide in 9:1 DMSO−methanol. The reactions of methoxide ion with hydroximoyl fluorides (X = F) are stereospecific. The reaction with 1Z (X = F) gives only the Z substitution product (1Z, X OCH3). The reaction of methoxide ion with 1E (X = F) is less selective, giving ca. 85% E substitution product. The Hammett ρ-values for
在9:1 DMSO-甲醇中,对O-甲基苯并氧肟基卤化物的Z和E异构体[ 1Z和1E,ArC(X)NOCH 3 ]与甲醇钠的反应进行了动力学和立体化学研究。甲醇离子与羟肟基氟化物(X = F)的反应是立体定向的。与1Z(X = F)的反应仅给出Z取代产物(1Z,X OCH 3)。甲醇离子与1E(X = F)的反应选择性较低,大约为。E替代品占85%。的哈米特ρ值Z和E异构体(X = F)分别为+2.94和+3.30。1Z(Ar = C 6 H 5)的元素效应为2.21(X = Br):1.00(X = Cl):79.7(X = F)。所述1E元件效果(AR = C 6 H ^ 5)1.00(X = Cl)的:18.3(X = F)和(AR = 4-CH 3 OC 6 H ^ 4)1.97(X = Br的):1.00(X = Cl):12.1(X = F)。激活用于这些反应的熵是否定的(例如,Δ小号⧧
Mediating K<sup>+</sup>/H<sup>+</sup> Transport on Organelle Membranes to Selectively Eradicate Cancer Stem Cells with a Small Molecule
作者:Fang-Fang Shen、Sheng-Yao Dai、Nai-Kei Wong、Shan Deng、Alice Sze-Tsai Wong、Dan Yang
DOI:10.1021/jacs.0c02134
日期:2020.6.17
Molecules that are capable of disrupting cellular ion homeostasis offer unique opportunities to treat cancer. However, previously reported synthetic ion transporters showed limited value as promiscuous ionic disruption caused toxicity to both healthy cells and cancercells indiscriminately. Here we report a simple yet efficient synthetic K+ transporter that takes advantage of the endogenous subcellular