Bao Ming, Bohórquez Arnold R Romero, Arman Hadi, Doyle Michael P
Department of Chemistry, The University of Texas at San Antonio San Antonio Texas 78249 USA
Grupo de Investigación en Compuestos Orgánicos de Interés Medicinal (CODEIM), Parque Tecnológico Guatiguará, Universidad Industrial de Santander A. A. 678 Piedecuesta Colombia.
Chem Sci. 2024 Jun 28;15(30):12042-12046. doi: 10.1039/d4sc03558e. eCollection 2024 Jul 31.
Highly selective formal [4 + 2]-cycloaddition of vinyldiazoacetates with azoalkenes from α-halohydrazones, as well as with cyclopentadiene and furan, occurs with light irradiation at room temperature, producing highly functionalized heterocyclic and bicyclic compounds in good yields and excellent diastereoseletivity. Under blue light these vinyldiazoacetate reagents selectively form unstable cyclopropenes that undergo intermolecular cycloaddition reactions at a faster rate than their competitive ene dimerization. [4 + 2]-cycloaddition of vinyldiazoacetates with formed azoalkenes produces bicyclo[4.1.0]tetrahydropyridazine derivatives and, together with their cycloaddition using cyclopentadiene and furan that form tricyclic compounds, they occur with high chemoselectivity and diastereocontrol, good functional group tolerance, and excellent scalability. Subsequent transformations portray the synthetic versatility of these structures.
乙烯基重氮乙酸酯与由α-卤代腙生成的偶氮烯烃以及与环戊二烯和呋喃发生高度选择性的形式上的[4 + 2]环加成反应，在室温下光照时即可发生，能以良好的产率和出色的非对映选择性生成高度官能化的杂环和双环化合物。在蓝光照射下，这些乙烯基重氮乙酸酯试剂选择性地形成不稳定的环丙烯，其分子间环加成反应的速率比竞争性的烯反应二聚化反应更快。乙烯基重氮乙酸酯与生成的偶氮烯烃发生[4 + 2]环加成反应生成双环[4.1.0]四氢哒嗪衍生物，并且它们与环戊二烯和呋喃发生环加成反应形成三环化合物，这些反应具有高化学选择性和非对映选择性控制、良好的官能团耐受性以及出色的可扩展性。后续转化展示了这些结构的合成多功能性。
