Efficient Synthesis of 2,3-Disubstituted-1,3-benzoxazines by Chlorotrimethylsilane-Mediated Aza-Acetalizations of Aromatic Aldehydes
作者:Zilong Tang、Zhonghua Zhu、Lin Yan、Shuhong Chang、Hanwen Liu
DOI:10.1002/jhet.1590
日期:2013.8
3‐benzoxazines were prepared in moderate to good yields by aza‐acetalizations of aromatic aldehydes with 2‐(N‐substituted aminomethyl)phenols in the presence of chlorotrimethylsilane or SnCl4. It was found that chlorotrimethylsilane was more effective for the reaction, especially for the reaction of fluorobenzaldehyde, and thereby, an efficientmethod for the preparation of 3,4‐dihydro‐2H‐1,3‐benzoxazines
一系列新颖的取代的3,4-二氢-2- ħ -1,3-苯并恶嗪在中度至良好的产率通过芳香醛与2-氮杂- acetalizations制备(ñ -取代氨基甲基)三甲基氯硅烷在或的SnCl存在酚4。发现氯三甲基硅烷对反应更有效,特别是对于氟苯甲醛的反应,因此,开发了一种有效的制备3,4-二氢-2 H -1,3-苯并恶嗪的方法。化合物的结构通过FT-IR,1 H NMR,13 C NMR,MS和元素分析确定。
Strategies for the synthesis of HBGl3 , a glutamic acid derived ligand bearing phenolic and azacarboxylate donor groups at the nitrogen atom
作者:Raminder S. Mulla、Melissa T. Walden、Dmitry S. Yufit、Tanya Desa、Elena Lurie-Luke、J.A. Gareth Williams
DOI:10.1016/j.tet.2017.09.032
日期:2017.11
The development of a route applicable to the preparation of acyclic glutamic acid-based chelating ligands bearing two different auxiliary donor groups linked to the nitrogenatom by methylene spacers is described and applied to the synthesis of the new polydentate ligand HBGl3, the first example of such a structure. The synthesis is accomplished using a strategy employing reductive amination and t-butyl