Photochemical reaction of 2,4,4,6-tetrasubstituted 1,4-dihydropyridines in deaerated media: photocolouration and photorearrangement accompanying dehydrogenation
作者:Junko Shibuya、Mami Nabeshima (née Nakamura)、Hajime Nagano、Koko Maeda
DOI:10.1039/p29880001607
日期:——
solutions and gave 1,3-diphenyl-2-azatriphenylene (8), 3-p-bromophenyl-2,4,6-triphenyl-pyridine (9), and 2,3,6-triphenyl-4-p-tolylpyridine (11), respectively. These reactions proceed through di-π-methane rearrangement accompanying dehydrogenation. 4-Benzyl-2,4,6-triphenyl-1,4-dihydro-pyridine (5) and 4-benzyl-1-methyl-2,4,6-triphenyl-1,4-dihydropyridine (6) showed very faint colouration on irradiation. Compound
脱气溶液中2,2,4,6-四苯基-1,4-二氢吡啶(1)的光化学颜色变化已报告为光致变色现象,是无可逆转的变化,可产生无色至紫色。 2,3,4,6-四苯基吡啶(7)为主要产物。螺-[2,6-二苯基-1,4-二氢吡啶-4,9'-芴](2),4-对-溴苯基-2,4,6-三苯基-1,4-二氢吡啶(3)和2,4,6-三苯基-4- p -甲苯基-1,4-二氢吡啶(4)也显示在脱气的溶液类似photocolour变化并给出1,3-二苯基-2-氮杂三亚苯(8),3- p -溴苯基-2,4,6-三苯基吡啶(9)和2,3,6-三苯基-4-对甲苯基吡啶(11)。这些反应通过伴随脱氢的二-π-甲烷重排进行。4-苄基-2,4,6-三苯基-1,4-二氢吡啶(5)和4-苄基-1-甲基-2,4,6-三苯基-1,4-二氢吡啶(6)显示非常微弱照射时着色。化合物(5)得到2,4,6-三苯基吡啶(12),其通过消除苄基和氢而