Department of Chemistry, University at Albany, State University of New York, 1400 Washington Avenue, Albany, New York 12222, USA.
J Org Chem. 2011 Dec 2;76(23):9572-6. doi: 10.1021/jo201765j. Epub 2011 Oct 31.
The reaction of corannulene (C(20)H(10)) with 1,2-C(2)H(4)Hal(2) (Hal = Cl or Br) in the presence of AlCl(3) affords stable nonplanar carbocations C(20)H(10)CH(2)CH(2)Hal(+) (Hal = Cl (1) and Br (2)) with an -CH(2)CH(2)Hal moiety attached to the interior carbon atom of the bowl. In the analogous reaction with 1-bromo-2-chloroethane, the selective (up to 98%) abstraction of chloride is observed with the formation of cation 2. The molecular structures of bowl-shaped carbocations 1 and 2 crystallized as salts with AlCl(4)(-) counterions are revealed by single-crystal X-ray diffraction. The reaction of 2 with methanol or ethanol provides further decoration of the nonplanar polyarene upon the nucleophilic addition of alkoxy groups to the exterior carbon atom of the corannulene moiety. The (1)H NMR investigation of the corresponding products, C(20)H(10)(CH(2)CH(2)Br)(OCH(2)R) (R = H (3) and CH(3) (4)), shows the formation of intramolecular H···O and H···Br hydrogen bonds.
薁（C(20)H(10)）与 1,2-C(2)H(4)Hal(2)（Hal = Cl 或 Br）在 AlCl(3)存在下反应，生成稳定的非平面碳正离子 C(20)H(10)CH(2)CH(2)Hal(+)（Hal = Cl（1）和 Br（2）），其中 -CH(2)CH(2)Hal 部分连接在碗状分子的内部碳原子上。在与 1-溴-2-氯乙烷的类似反应中，观察到选择性（高达 98%）的氯化物的提取，形成阳离子 2。通过单晶 X 射线衍射揭示了作为 AlCl(4)(-)抗衡离子盐结晶的碗状碳正离子 1 和 2 的分子结构。阳离子 2 与甲醇或乙醇反应，通过亲核加成到薁部分的外部碳原子上，进一步修饰非平面多芳烃。相应产物 C(20)H(10)(CH(2)CH(2)Br)(OCH(2)R)（R = H（3）和 CH(3)（4））的（1）H NMR 研究表明形成了分子内的 H···O 和 H···Br 氢键。
