Photoinduced Molecular Transformations. Part 142. One‐step syntheses of 1H‐benz[f]indole‐4,9‐diones and 1H‐indole‐4,7‐diones by a new regioselective photoaddition of 2‐amino‐1,4‐naphthoquinones and 2‐amino‐1,4‐benzoquinones with alkenes
Photoinduced Molecular Transformations. Part 142. One‐step syntheses of 1H‐benz[f]indole‐4,9‐diones and 1H‐indole‐4,7‐diones by a new regioselective photoaddition of 2‐amino‐1,4‐naphthoquinones and 2‐amino‐1,4‐benzoquinones with alkenes
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DOI：
10.1002/hlca.19930760818
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发表时间：
1993-12
影响因子：
1.8
通讯作者：
K. Kobayashi;H. Takeuchi;S. Seko;Y. Kanno;S. Kujime;H. Suginome
中科院分区：
文献类型：
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作者：
K. Kobayashi;H. Takeuchi;S. Seko;Y. Kanno;S. Kujime;H. Suginome
2，3-二氢-1H-苯并[f]吲哚-4，9-二酮3a-d，h通过2-氨基-1，4-萘醌（1）与各种富电子烯烃2的前所未有的[3 + 2]区域选择性光加成以13-82%产率在一步反应中形成（方案1，表）。由1与乙烯基醚和乙酸乙烯酯衍生的[3 + 2]光加合物以33-72%的产率得到1H-苯并[f]吲哚-4，9-二酮4 e，f，i，通过从所得加合物中自发损失相应的醇或AcOH; 4 i具有卡那霉素骨架。[3 + 2]光加成也发生在不同取代的氨基-1，4-苯醌6、7和12与过量的烯烃2在苯中的照射下，分别得到1H-吲哚-4，7-二酮衍生物13和14（方案3）、15 a和16（方案4）以及18（方案4）。这些光加成反应的初始产物被证明是对苯二酚，其空气氧化产生杂环醌;在处理由2-氨基-5-苯基-1，4，7-三甲基-2，3-二氢-2-甲氧基-2-甲基-5-苯基-1H-吲哚-1，4，7-三基三乙酸酯（19）得到的粗光加成混合物后，4-苯醌（7）和2-甲氧基丙-1-烯（2f）与Ac_2O和吡啶在N_2下反应。提出了一种导致稠合对苯二酚的途径，该途径涉及由这些光加成中的电子转移产生的离子中间体（方案5）。
The 2,3-dihydro-1H-benz[f]indole-4,9-diones 3a–d, h were formed in a one-step reaction in 13–82% yield by an unprecedented [3 + 2] regioselective photoaddition of 2-amino-1,4-naphthoquinone (1) with various electronrich alkenes 2 (Scheme 1, Table). The [3 + 2] photoadducts derived from 1 with vinyl ethers and vinyl acetate gave 1H-benz[f]indole-4,9-diones 4e, f, i, in 33–72% yield, by spontaneous loss of the corresponding alcohol or AcOH from the resulting adducts; 4i has a kinamycin skeleton. The [3 + 2] photoaddition also took place on irradiation of the differently substituted amino-1,4-benzoquinones 6, 7, and 12 and excess alkenes 2 in benzene, giving 1H-indole-4,7-dione derivatives 13 and 14 (Scheme 3), 15a and 16 (Scheme 4), and 18 (Scheme 4), respectively. The initial products in these photoadditions were proved to be hydroquinones, the air oxidation of which yielded the heterocyclic quinones; 2,3-dihydro-2-methoxy-2-methyl-5-phenyl-1H-indole-1,4,7-triyl triacetate (19) was isolated after treatment of the crude photoaddition mixture obtained from 2-amino-5-phenyl-1,4-benzoquinone (7) and 2-methoxyprop-1-ene (2f) with Ac2O and pyridine under N2. A pathway leading to the annelated hydroquinones involving ionic intermediates arising from an electron transfer in these photoadditions is proposed (Scheme 5).