Dabbs Jonathan D, Taylor Caleb C, Livaudais Benjamin F, Meng Alvin Q, Quillin Brian T, Dickie Diane A, Harman W Dean
Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States.
Organometallics. 2025 Aug 15;44(17):1920-1925. doi: 10.1021/acs.organomet.5c00199. eCollection 2025 Sep 8.
The Zincke reaction combines a pyridinium salt bearing an -withdrawing group and a primary aliphatic amine to form an alkylated pyridinium salt through a ring-opening/ring-closing sequence. Herein, we explore the analogous reaction sequence for a pyridinium salt η-bound to a transition metal. We find that the -sulfonylated pyridinium ligand (pyR, where R = mesyl or tosyl) of [WTp-(NO)-(PMe)-(η-pyR)]-OTf selectively reacts with a primary amine, and the resulting 2-aminodihydropyridine complex then undergoes a tungsten-stabilized ring-scission to form the corresponding η-azatriene complex. Subsequent ring-closure between the newly installed amine and the sulfonylated imine results in a new aminodihydropyridinium species. This dihydropyridinium resists rearomatization due to a stabilizing influence of the tungsten fragment. Subsequent displacement of the sulfonamide by pendent heteroatoms leads to the formation of new heterocyclic frameworks. Herein the syntheses of 30 heterocyclic complexes are described (3 characterized by SC-XRD) including 7 examples of multicyclic systems.
津克反应将带有吸电子基团的吡啶鎓盐与伯脂肪胺结合，通过开环/闭环序列形成烷基化吡啶鎓盐。在此，我们探索了与过渡金属η键合的吡啶鎓盐的类似反应序列。我们发现，[WTp-(NO)-(PMe)-(η-pyR)]-OTf的-磺酰化吡啶鎓配体（pyR，其中R = 甲磺酰基或对甲苯磺酰基）与伯胺选择性反应，生成的2-氨基二氢吡啶配合物随后发生钨稳定的环开裂，形成相应的η-氮杂三烯配合物。新引入的胺与磺酰化亚胺之间随后的闭环反应生成新的氨基二氢吡啶鎓物种。由于钨片段的稳定作用，该二氢吡啶鎓抗拒芳构化。随后，侧链杂原子取代磺酰胺导致形成新的杂环骨架。本文描述了30种杂环配合物的合成（3种通过单晶X射线衍射表征），包括7个多环体系的例子。
