(5‐Imino‐4,5‐dihydro‐3H‐pyrrol‐2‐yl)amines as Sterically Restrained 1,3,5‐Triazapenta‐1,3‐dienes: Useful Building Blocks for the Synthesis of Oligonitriles
(5‐Imino‐4,5‐dihydro‐3H‐pyrrol‐2‐yl)amines as Sterically Restrained 1,3,5‐Triazapenta‐1,3‐dienes: Useful Building Blocks for the Synthesis of Oligonitriles
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(5-亚氨基-4,5-二氢-3H-吡咯-2-基)胺作为空间限制的1,3,5-三氮杂五环-1,3-二烯：用于合成低聚腈的有用结构单元
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发表时间：
2007
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通讯作者：
E. Würthwein
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作者：
Edgar A. Marihart;J. Greving;R. Fröhlich;E. Würthwein
（5-亚氨基-4，5-二氢-3H-吡咯-2-基）胺2可被认为是空间受限的1，3，5-三氮杂五-1，3-二烯。它们很容易从2，2，3，3-四甲基丁二腈（1）和氨基化锂制备，随后进行水处理，得到单环化合物2a-d和双环和三环化合物2 e-g。X射线衍射研究2c和2d，其中包含一个主要的NH 2基团，揭示了存在的同源二聚体举行在一起的配对氢键在固态。通过苯甲酰氯捕获锂化中间体2a-Li提供了获得1-氧杂-3，5，7-三氮杂庚-1，3，5-三烯3b的途径。其特征在于在固体状态下由平面杂环亚基和强烈扭曲的N-酰基脒部分。化合物2a、B、d或2a-Li与1-氧杂-3，5-二嗪鎓盐4反应，得到1-氧杂-3，5，7，9，11-五氮杂十一碳-1，3，5，7，9-五烯5a-d。这里，平面杂环部分联合收割机与较长的扭曲（非螺旋）低聚腈部分结合。5d的X射线衍射研究表明，在固态下，分子间的N-H···O=C氢键，产生一维链。以与1类似的方式，偶氮异丁腈（AIBN）热分解的副产物三腈2，3，5-三甲基-2，3，5-三氰基己烷（6）与苄基氨基锂反应，得到双环中间体，当用1-氧杂-3，5，7，9，11，13-六氮杂十三碳-1，3，5，7，9，11-六烯7处理时，该双环中间体成功地转化为相应的1-氧杂-3，5，7，9，11-六烯7，5-二嗪鎓盐4 b.类似于5d，这种延伸的低聚腈在固态下形成一维氢键聚合物。其UV光谱（λmax = 286 nm）被解释为平面共轭π-π* 氮杂多烯亚结构被杂环强制成平面性。（© Wiley-VCH Verlag GmbH & Co. KGaA，69451魏因海姆，德国，2007）
(5-Imino-4,5-dihydro-3H-pyrrol-2-yl)amines 2 may be considered as sterically restrained 1,3,5-triazapenta-1,3-dienes. They were easily prepared from 2,2,3,3-tetramethylsuccinonitrile (1) and lithium amides with subsequent aqueous workup to give the monocyclic compounds 2a–d and the bi- and tricyclic compounds 2e–g. X-ray diffraction studies of 2c and 2d, which contain a primary NH2 group, reveal the existence of homodimers held together with paired hydrogen bonds in the solid state. Trapping of the lithiated intermediate 2a-Li by benzoyl chloride provided access to the 1-oxa-3,5,7-triazahepta-1,3,5-triene 3b. It is characterized in the solid state by a planar heterocyclic subunit and a strongly twisted N-acylamidine part. With 1-oxa-3,5-diazinium salts 4, compounds 2a,b,d or 2a-Li reacted to give 1-oxa-3,5,7,9,11-pentaazaundeca-1,3,5,7,9-pentaenes 5a–d. Here again, the planar heterocyclic parts combine with longer, twisted (not helical) oligonitrile moieties. The X-ray diffraction study of 5d indicates intermolecular N–H···O=C hydrogen bonding in the solid state, producing one-dimensional strands. In a similar way as 1 the trinitrile 2,3,5-trimethyl-2,3,5-tricyanohexane (6), a byproduct of the thermal decomposition of azoisobutyronitrile (AIBN), reacted with lithium benzylamide to give a bicyclic intermediate which was successfully converted into the corresponding 1-oxa-3,5,7,9,11,13-hexaazatrideca-1,3,5,7,9,11-hexaene 7 when treated with 1-oxa-3,5-diazinium salt 4b. Similar to 5d, this extended oligonitrile forms one-dimensional hydrogen-bonded polymers in the solid state. Its UV spectrum (λmax = 286 nm) is interpreted in terms of a planar conjugated π–π* azapolyene substructure forced into planarity by the heterocycles.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)