Bi Hongyan, Shen Chaoren, Wang Sunewang R
Chang-Kung Chuang Institute, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, 200241, China.
Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, East China Normal University, Shanghai, 200241, China.
Angew Chem Int Ed Engl. 2025 Jan 15;64(3):e202415839. doi: 10.1002/anie.202415839. Epub 2024 Nov 14.
In contrast to the locked fluxionality of norcaradienes fused by benzene, unexplored less aromatic heterole-fused norcaradienes, creatively generated by intramolecular hydroarylation of heteroaryl alkynylcyclopropanes, reserve a balancing fluxionality that permits a dearomative [1,5]-sigmatropic carbon shift of norcaradienes akin to the reduced aromaticity of heterole. This "walk" shift was confirmed by the isolation of a cycloheptatriene species derived from ring-expansion of a dearomatized alkynylated heterole-fused norcaradiene. A following ester-directed ring-opening rearomatization of these dearomatized heterole-fused norcaradienes gives the products featuring migratory acylmethyls that are competent for helicenation with the neighboring (hetero) arenes via (formal) dehydrative alkenylation. Such balancing reactivity of heterole-fused norcaradienes will open up the opportunity for the development of controllable reactions of fused norcaradienes.
与苯稠合的降蒈二烯的锁定流动性不同，通过杂芳基炔基环丙烷的分子内氢芳基化创造性地生成的未被探索的较少芳香性的杂环稠合降蒈二烯保留了一种平衡的流动性，这种流动性允许降蒈二烯发生类似于杂环降低的芳香性的脱芳香[1,5]-西格玛重排碳迁移。这种“行走”重排通过分离出一种由脱芳香化的炔基化杂环稠合降蒈二烯扩环得到的环庚三烯物种得到证实。这些脱芳香化的杂环稠合降蒈二烯随后的酯导向开环再芳香化反应得到了具有迁移酰基甲基的产物，这些产物能够通过（形式上的）脱水烯基化与相邻的（杂）芳烃进行螺旋烯化。杂环稠合降蒈二烯的这种平衡反应性将为开发稠合降蒈二烯的可控反应提供机会。
