Photochemical Synthesis of Prochiral Dialkyl 3,3-Dialkylcyclopropene-1,2-dicarboxylates with Facial Shielding Substituents and Related Substrates
作者:A. Stephen K. Hashmi、Marc A. Grundl、Andreas Rivas Nass、Frank Naumann、Jan W. Bats、Michael Bolte
DOI:10.1002/1099-0690(200112)2001:24<4705::aid-ejoc4705>3.0.co;2-j
日期:2001.12
types of cyclopropene-1,2-dicarboxylates 1 have been obtained by photochemical methods from the corresponding pyrazoles 11, 12, or 13. These pyrazoles were synthesized by 1,3-dipolar cycloadditions of alkynes 8 or 9 with either preformed diazoalkanes or diazoalkanes generated photochemically in situ, by use of oxadiazolines as diazoalkane precursors. The numerous substrates have clearly established the
通过光化学方法从相应的吡唑 11、12 或 13 中获得了不同类型的环丙烯-1,2-二羧酸酯 1。这些吡唑是通过炔烃 8 或 9 与预先形成的重氮烷烃或重氮烷烃的 1,3-偶极环加成反应合成的通过使用恶二唑啉作为重氮烷前体,光化学原位产生。众多的底物明确规定了不同途径合成前体和环丙烯的范围和局限性;甚至可以合成前手性和对映体纯的手性衍生物。许多前体和环丙烯可以通过 X 射线晶体结构分析进行表征,这揭示了有趣的结构特征,并允许明确指定不同的非对映异构体或结构异构体。一些光化学反应产生了独特的副产物;晶体结构分析对于明确的结构分配绝对至关重要。