Adcock William, Blokhin Andrei V., Elsey Gordon M., Head Nicholas H., Krstic Alexander R., Levin Michael D., Michl Josef, Munton Jamie, Pinkhassik Evgueni, Robert Marc, Savéant Jean-Michel, Shtarev Alexander, Stibor Ivan
Department of Chemistry, The Flinders University of South Australia, Adelaide, Australia, 5001, Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, Department of Chemical Sciences, Deakin University, Geelong, Victoria, Australia 3217, Laboratoire a' Electrochimie Moléculaire de L'Université Denis Diderot (Paris 7), 2 place Jussieu, 75251 Paris Cedex 05, France, and Institute of Chemical Technology, Prague, Czech Republic.
J Org Chem. 1999 Apr 16;64(8):2618-2625. doi: 10.1021/jo982124o.
A series of 3-halo-substituted bicyclo[1.1.1]pentane-1-carboxylic acids 1 (Y = COOH; X = F, Cl, Br, I, and CF(3)) as well as the parent compound 1 (Y = COOH, X = H) have been prepared, and a study of some of their properties have been made. It was found that their reactions with xenon difluoride cover a wide range of reactivities. On one hand, the fluoro acid 1 (Y = COOH, X = F) displayed no apparent reaction at all while, on the other, the bromo acid 1 (Y = COOH, X = Br) and parent compound 1 (Y = COOH, X = H) underwent ready reaction with complete disintegration of the ring system. A possible explanation is advanced based on polar kinetic and thermodynamic effects governing the lifetime of an intermediate acyloxy radical species. The relative ease of oxidation of the carboxylates 1 (Y = COO(-); X = H, F, Cl, Br, I, CF(3), and COOCH(3)), as mirrored by their peak oxidation potential values (E(p)) determined by cyclic voltammetry, also covers a wide range. These data coupled with the dissociation constants (pK(a)) of some of the acids 1 (Y = COOH; X = H, F, Cl, and CF(3)) reflect significantly on the modes of transmission of electronic effects acting through the bicyclo[1.1.1]pentane ring system.
已制备出一系列3-卤代双环[1.1.1]戊烷-1-羧酸1（Y = COOH；X = F、Cl、Br、I和CF(3)）以及母体化合物1（Y = COOH，X = H），并对它们的一些性质进行了研究。发现它们与二氟化氙的反应具有广泛的反应活性。一方面，氟代酸1（Y = COOH，X = F）根本没有明显反应，而另一方面，溴代酸1（Y = COOH，X = Br）和母体化合物1（Y = COOH，X = H）则很容易发生反应，环系完全分解。基于控制中间体酰氧基自由基寿命的极性动力学和热力学效应，提出了一种可能的解释。通过循环伏安法测定的羧酸盐1（Y = COO(-)；X = H、F、Cl、Br、I、CF(3)和COOCH(3)）的峰值氧化电位值（E(p)）所反映的它们相对容易被氧化的程度也涵盖了很广的范围。这些数据与一些酸1（Y = COOH；X = H、F、Cl和CF(3)）的解离常数（pK(a)）一起，显著反映了通过双环[1.1.1]戊烷环系起作用的电子效应的传递模式。
