Synthesis of Dibenzo[<i>d</i>,<i>f</i>][1,3]Diazepines via Elemental Sulfur-Mediated Cyclocondensation of 2,2′-Biphenyldiamines with 2-Chloroacetic Acid Derivatives
作者:Tatyana A. Tikhonova、Konstantin A. Lyssenko、Igor V. Zavarzin、Yulia A. Volkova
DOI:10.1021/acs.joc.9b02002
日期:2019.12.20
three-component reaction of 2,2'-biphenyldiamines with 2-chloroacetic acid derivatives and elemental sulfur was developed for the practical synthesis of unknown 2-carboxamide-substituted dibenzo[d,f][1,3]diazepines. This protocol is distinguished by efficiency in water and good tolerance to functional groups and can be adapted to a large-scale synthesis. The chemoselective preparation of a variety of
versatile method for the chemoselective Boc protection of amines has been developed by a treatment with (Boc)2O in the presence of sulfonic-acid-functionalized silica as a catalyst. The method is general for the preparation of N-Boc derivatives of aliphatic (acyclic and cyclic), aromatic, and heteroaromatic amines; primary and secondary amines; aminols, amino-esters; and sulfonamides. The catalyst works
We synthesized various carbazoles from anilines through a three-step process with good overall yields (up to 48%). This process comprises N-acetylation, copper(0)-mediated Ullmann homocoupling, and acid-mediated intramolecular amination. It permits various functional groups on the substrate. Scale-up of the developed three-step synthetic route to carbazoles was also demonstrated.
Highly Chemoselective Access to 2,2′-Diaminobiaryls via Ni-Catalyzed Protecting-Group-Free Coupling of 2-Haloanilines
作者:Cheng-Yu Long、Shao-Fei Ni、Min-Hui Su、Xue-Qiang Wang、Weihong Tan
DOI:10.1021/acscatal.0c03428
日期:2020.11.20
development of strategies to access 2,2′-diaminobiaryl derivatives via a transition-metal-catalyzed coupling reaction from protecting-group-free starting materials is a challenging task to accomplish, owing to the easy occurrence of undesired side reactions. The exploitation of Ni-catalyzed direct homocoupling of unprotected 2-haloaniline analogues to produce 2,2′-diaminobiaryls with a readily available