Substituent Effects and Charge Delocalization Mode in Chrysenium, Benzo[<i>c</i>]phenanthrenium, and Benzo[<i>g</i>]chrysenium Cations: A Stable Ion and Electrophilic Substitution Study
作者:Kenneth K. Laali、Takao Okazaki、Subodh Kumar、Sergio E. Galembeck
DOI:10.1021/jo001268b
日期:2001.2.1
disubstituted chrysenes Ch (5- methyl- 3, 2-methoxy- 19, 2-methoxy-11-methyl- 20, 2-methoxy-5-methyl- 21, and 9-methyl-4H-cyclopenta[def]chrysene 22), monosubstituted benzo[c]phenanthrenes BcPh (3-methoxy- 23, 3-hydroxy- 24), and monosubstituted benzo[g]chrysenes BgCh (12-methoxy- 25; 12-hydroxy- 26) were generated in FSO3H/SO2ClF or FSO3H-SbF5 (4:1)/SO2ClF and studied by low-temperature NMR at 500 MHz. The methoxy
衍生自单取代和双取代的Ch(5-甲基-3、2-甲氧基-19、2-甲氧基-11-甲基-20、2-甲氧基-5-甲基-21和9-甲基-4H-环戊[def] ch 22),单取代的苯并[c]菲BcPh(3-甲氧基-23、3-羟基-24)和单取代的苯并[g] ch BgCh(12-甲氧基25; 12-羟基26)在FSO3H / SO2ClF或FSO3H-SbF5(4:1)/ SO2ClF中生成,并通过500 MHz的低温NMR研究。甲氧基和甲基取代基将质子化指向它们各自的邻位。母体Ch 1在C-6 / C-12质子化,而3在C-6(3aH +)和C-12(3bH +)质子化,后者是热力学阳离子。2-甲氧基-Ch 19在C-1处质子化,得到两个构象上不同的碳鎓离子(19aH + / 19bH +)。在二取代的Ch衍生物20和21中,2-甲氧基取代了5-甲基,并且形成的主要碳阳离子通过对甲氧基的邻位攻击