An arguable expectation in halogen chemistry is that an amine will react oxidatively with an N-halosuccinimide (NXS) to form an N-halogenated species bearing a covalent N−X bond. While likely for NCS under most conditions, we find this expectation simply not true for NIS and largely inaccurate for NBS. Herein, we disclose evidence through systematic NMR and X-ray studies that non-covalent halogen bonded amine complexes of NIS predominate over covalent N-halogenated species, even with primary and secondary amines. For example, during the catalytic electrophilic halocyclization of gem-disubstituted alkenes by cinchona-like amines, the quinuclidine complexes of NIS and NBS display lower reactivity than their parent N-halosuccinamides and require the presence of an appropriate Brønsted acid. Specifically, a Brønsted acid and quinuclidine jointly catalyze the halo-cycloetherification of γ-alkenyl alcohols with NIS or NBS, while only quinuclidine acts as a catalyst in the halolactonization of γ-alkenoic acids. Although our evidence confirms a transient N-halogenated quaternary ammonium salt as the halonium species, it is important to note that NIS predominantly forms ‘off-cycle’ halogen bonded amine complexes in solution.

中文翻译：

---

N-卤代琥珀酰亚胺与胺的卤素键合以及布朗斯台德酸在奎宁环催化卤环化反应中的作用

卤素化学中一个有争议的预期是胺将与N-卤代琥珀酰亚胺 (NXS)氧化反应以形成带有共价NX 键的N-卤代物质。虽然在大多数情况下可能适用于 NCS，但我们发现这种期望对于 NIS 根本不正确，并且对于 NBS 来说很大程度上是不准确的。在此，我们通过系统的 NMR 和 X 射线研究公开了证据，表明 NIS 的非共价卤素键合胺复合物优于共价N-卤化物质，即使是伯胺和仲胺。例如，催化电halocyclization期间宝石由金鸡纳状胺，奎宁环NIS和NBS的络合物二取代的烯烃显示较低的反应性比它们的亲本Ñ-卤代琥珀酰胺，需要适当的布朗斯台德酸。具体而言，布朗斯台德酸和奎宁环共同催化 γ-烯醇与 NIS 或 NBS 的卤代环醚化，而只有奎宁环在 γ-烯酸的卤代内酯化中起催化剂作用。尽管我们的证据证实了瞬态N卤化季铵盐是卤化物，但重要的是要注意 NIS 主要在溶液中形成“非循环”卤素键合胺复合物。