Azo Bridges from Azines, XXIII. 1,5-Laticyclic Conjugation Between Parallel Azo ando-Phenylene Bridges. Structure Dependence of [6 + 2] Photocycloadditions
作者:Karin Beck、Uwe Brand、Siefried Hünig、Hans-Dieter Martin、Bernhard Mayer、Karl Peters、Hans Georg von Schnering
DOI:10.1002/jlac.199619961125
日期:1996.11
rigid parallelo o-phenylene and azo bridges are connected to five- and/or six-membered carbocyclic moities. The o-phenylene bridge was introduced by two routes: (A) starting from precursors already containing that bridge (24, 29) and assembling the azo bridge in consecutive steps ( 3a, 3b, 5c, 5d, 5e, 5f, 5g); (B) starting from the systems with parallel CC/NN bridges (9a, 11a, 13a, 42) and completing
合成了四个系统1、3、5和7的示例,其中刚性平行六烷基邻苯撑和偶氮桥连接到五元和/或六元碳环部分。所述Ô亚苯基桥通过两种途径引入:(A)从已经包含桥(前体开始24,29)及装配在连续的步骤的偶氮桥(3A,3B,5C,5D,5E,5F,5G); (B)从具有平行CC / NN桥(9a,11a,13a,42)的系统开始,并通过四氯噻吩二氧化物完成二氢邻苯撑环。偶氮桥的正离子氢转移增强了中间体二氢芳烃的脱氢作用ø亚苯基衍生物(22,3CH 2,25)。多米诺氢转移44 45 5h证明了这一机理。通过路线B,获得系统1a,1b,3c,3d,5a,5b,5h和43。与此形成鲜明对比的是平滑的[2 + 2]的系统光环9,11,13,和15(CC / NN桥),[6 + 2]光环只发生与系统1和(5 ç / 5 Ñ)和3(6 C / 5 N),但不适用于系统5(5 C / 6 N)和7(6 C / 6