Department of Chemistry, Rutgers University, 73 Warren Street, Newark, NJ 07102, USA.
Department of Chemistry, Wroclaw University, F. Joliot-Curie 14, Wroclaw, 50-383, Poland.
Angew Chem Int Ed Engl. 2022 Aug 26;61(35):e202207346. doi: 10.1002/anie.202207346. Epub 2022 Jul 26.
Amide bond replacement with planar isosteric chalcogen analogues has an important implication for the properties of the N-C(X) linkage in structural chemistry, biochemistry and organic synthesis. Herein, we report the first higher chalcogen derivatives of non-planar twisted amides. The synthesis of twisted thioamide in a versatile system has been accomplished by direct thionation without cleavage of the σ N-C bond. The synthesis of twisted selenoamide has been accomplished by selenation with Woollins' reagent. The structures of higher chalcogen analogues of non-planar amides were unambiguously confirmed by X-ray crystallography. Reactivity studies were conducted to determine the effect of isologous N-C(O) to N-C(X) replacement on the properties of the amide linkage. Computational studies were employed to evaluate structural and energetic parameters of amide bond alteration in higher chalcogen amides. The study provides the first experimental evidence on the effect of chalcogen isologues on the structural and electronic properties of the non-planar amide N-C(X) linkage.
酰胺键被平面等排的拟卤代物替代，这对结构化学、生物化学和有机合成中 N-C(X)键的性质有重要意义。在此，我们报告了首例非平面扭曲酰胺的较高拟卤代物。通过直接硫代作用而不切断σ N-C 键，在多功能体系中完成了扭曲硫代酰胺的合成。用 Woollins 试剂进行硒化作用完成了扭曲硒代酰胺的合成。非平面酰胺的较高拟卤代物的结构通过 X 射线晶体学得到了明确的证实。进行了反应性研究，以确定等排 N-C(O) 到 N-C(X) 取代对酰胺键性质的影响。还采用计算研究评估了较高拟卤代酰胺中酰胺键改变的结构和能量参数。该研究提供了首例关于拟卤代物对非平面酰胺 N-C(X)键的结构和电子性质影响的实验证据。
