1629-17-0Relevant academic research and scientific papers
Photocatalyst- And Transition-Metal-Free Visible-Light-Promoted Intramolecular C(sp2)-S Formation
Wang, Hao,Wu, Qi,Zhang, Jian-Dong,Li, Hai-Yan,Li, Hong-Xi
supporting information, p. 2078 - 2083 (2021/04/05)
A photocatalyst- and transition-metal-free visible-light-induced cyclization of ortho-halothiobenzanilides has been developed. Upon irradiation with visible light, substrates undergo dehalogenative cyclization to 2-aryl benzothiazoles with high efficiency and selectivity. This photocyclization exhibits a high tolerance to various functional groups, is applicable for the synthesis of 2-alkyl benzothiazoles, and is easy to set up for gram-scale reaction.
Practical bromination of arylhydroxylamines with SOBr2 towards ortho-bromo-anilides
Du, Yuanbo,Feng, Lei,Gao, Hongyin,Guo, Lirong,Lu, Haifeng,Xi, Zhenguo
supporting information, (2021/05/19)
A facile approach for synthesizing ortho-bromoanilides from readily available aryhydroxylamines and thionyl bromide is demonstrated in this work. Mild reaction conditions and broad scope of substrates ranging from heterocyclic structures to pharmaceutics-potential motifs are used in the reactions of this paper. Efficient bromination of ortho C–H bonds of the aryhydroxylamines has been achieved. Ortho-bromoanilide products were obtained in good to excellent yields, and model scaled-up reactions of this synthetic approach are shown in this work.
Parallel synthesis of a library of benzoxazoles and benzothiazoles using ligand-accelerated copper-catalyzed cyclizations of ortho-halobenzanilides
Evindar, Ghotas,Batey, Robert A.
, p. 1802 - 1808 (2007/10/03)
A general method for the formation of benzoxazoles via a copper-catalyzed cyclization of ortho-haloanilides is reported. This approach complements the more commonly used strategies for benzoxazole formation which require 2-aminophenols as substrates. The reaction involves an intramolecular C-O cross-coupling of the ortho-haloanilides and is believed to proceed via an oxidative insertion/reductive elimination pathway through a Cu(I)/Cu(III) manifold. The reaction is also applicable to the formation of benzothiazoles. A variety of ligands including 1,10-phenanthroline and N,N′- dimethylethylenediamine were shown to provide ligand acceleration/stabilization in the reaction. Optimal conditions for cyclization used a catalyst combination of CuI and 1,10-phenanthroline (10 mol %). The method was amenable to a parallel-synthesis approach, as demonstrated by the synthesis of a library of benzoxazoles and benzothiazoles substituted at various positions in the ring. Most examples utilized the cyclization of ortho-bromoanilides, but orthoiodoanilides and ortho-chloroanilides also undergo a reaction under these conditions. The rate of reaction of the ortho-haloanilides follows the order I > Br > Cl, consistent with oxidative addition being the rate-determining step.
