A concise strategy to prepare polycyclic heteroaromatics involving a deaminative contraction cascade is detailed. The efficient deaminative ring contraction involves the in situ methylation of a biaryl-linked dihydroazepine to form a cyclic ammonium cation that undergoes a base-induced [1,2]-Stevens rearrangement/dehydroamination sequence. The presence of pseudosymmetry guides the retrosynthetic analysis
详细介绍了涉及脱
氨基收缩级联的制备多环杂
芳烃的简明策略。有效的脱
氨环收缩涉及联芳基连接的二氢吖庚因的原位甲基化,形成环状
铵阳离子,该阳离子经历碱诱导的[1,2]-史蒂文斯重排/脱氢
氨化序列。假对称性的存在指导了含
吡啶基多环杂
芳烃的逆合成分析,使其能够通过叔胺前体的还原环化和脱
氨收缩来构建。