Enantioselective Synthesis of Distorted π-Extended Chiral Triptycenes Consisting of Three Distinct Aromatic Rings by Rhodium-Catalyzed [2+2+2] Cycloaddition
Enantioselective Synthesis of Distorted π-Extended Chiral Triptycenes Consisting of Three Distinct Aromatic Rings by Rhodium-Catalyzed [2+2+2] Cycloaddition
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DOI：
10.1002/chem.201905519
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发表时间：
2020-01-30
影响因子：
4.3
通讯作者：
Tanaka, Ken
中科院分区：
文献类型：
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作者：
Aida, Yukimasa;Shibata, Yu;Tanaka, Ken
2，2‘-二(prop-1-yn-1-yl)-5，5’-二(三氟甲基)-1，1‘-联苯与6-甲氧基-1，2-二氢萘的非对映选择性Diels-Alder反应和芳构化反应，实现了2，2’-二(prop-1-yn-1-yl)-5，5‘-二(三氟甲基)-1，1’-联苯与6-甲氧基-1，2-二氢萘的非对映选择性Diels-Alder反应和芳构化反应。通过C-O键裂解反应合成了去甲氧基衍生物。在这种合成中，使用缺电子的双炔和富电子的烯烃对于抑制不必要的缓解应变的碳正离子重排和稳定扭曲的三茂铁烯结构是至关重要的。
The enantioselective synthesis of distorted pi-extended chiral triptycenes, consisting of three distinct aromatic rings, has been achieved with high ee value of 87 % by the cationic rhodium(I)/segphos complex-catalyzed enantioselective [2+2+2] cycloaddition of 2,2 '-di(prop-1-yn-1-yl)-5,5 '-bis(trifluoromethyl)-1,1 '-biphenyl with 6-methoxy-1,2-dihydronaphthalene followed by the diastereoselective Diels-Alder reaction and aromatization. Demethoxy derivatives were also synthesized by the C-O bond cleavage. In this synthesis, the use of the electron-deficient diyne and the electron-rich alkene is crucial to suppress the undesired strain-relieving carbocation rearrangement and stabilize the distorted triptycene structure.