Fused Multifunctionalized Chromenes from Tetraynes and ,-Unsaturated Aldehydes
Fused Multifunctionalized Chromenes from Tetraynes and ,-Unsaturated Aldehydes
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来自四炔和 ,-不饱和醛的稠合多功能色烯
DOI：
10.1002/chem.201701009
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
Hu Yimin
中科院分区：
文献类型：
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作者：
Meng Xiangzhen;Lv Shuang;Cheng Dong;Hu Qiong;Ma Jie;Liu Baohua;Hu Yimin
据报道，在四炔的一锅三步级联六脱氢-狄尔斯-阿尔德反应中合成稠合的、高度取代的色烯，然后进行分子间 α,β-不饱和醛重排。通过丙二酸酯与3-溴-1-丙炔的缩合制备了目标化合物，所得2,2-二(1-丙炔-3-基)丙二酸酯与苯乙炔基溴交叉偶联得到2,2-二(5-苯基-2,4-戊二炔基)丙二酸酯，其进行分子内环化生成三环色烯。整个转变涉及通过分子内环化和分子间重排反应形成四个新的CC键和一个新的C-芳基-O-C-芳基键。这些构成了构建高度取代的天然色烯核心的关键策略以及生产其他色烯的稳健方法。
The synthesis of fused, highly substituted chromenes in a one‐pot‐three‐step cascade hexadehydro‐Diels–Alder reaction of tetraynes followed by an intermolecular α,β‐unsaturated aldehyde rearrangement is reported. The target compounds were prepared by the condensation of malonates with 3‐bromo‐1‐propyne, and the resulting 2,2‐di(1‐propyn‐3‐yl)malonates underwent cross‐coupling with phenylethynyl bromides to afford 2,2‐di(5‐phenyl‐2,4‐pentadiynyl)malonates, which underwent intramolecular cyclization to produce tricyclic chromenes. The overall transformation involves the formation of four new C−C bonds and one new C‐aryl−O−C‐aryl bond by both intramolecular cyclization and intermolecular rearrangement reactions. These constitute a key strategy for the construction of a highly substituted natural chromene core and a robust method for producing other chromenes.