A Review on Domino Condensation/Cyclization Reactions for the Synthesis of 2‐Substituted 1,3‐Benzothiazole Derivatives

Abstract

Domino reactions serve as one of the most step-economical methods for the synthesis of benzoxazole molecules such as 2-substituted 1,3-benzothiazoles. Recently, a variety of compounds were found to facilitate these domino reactions.[a] 408 Scheme 1. The recent developments to obtain 2-substituted 1,3-benzothiazoles by using various cyclization reagents in a domino manner.

Modern Approaches to the Synthesis and Transformations of Practically Valuable Benzothiazole Derivatives

“…Benzothiazoles, as a bicyclic heterocycles with fused benzene and thiazole rings containing electron-rich heteroatoms, nitrogen and sulfur, attract great interest from researchers for drug design due to their high biological and pharmacological activity [ 1 , 2 , 3 , 4 , 5 ]. The present review covers the literature from 2015.…”

Consecutive Oxidation/Condensation/Cyclization/Aromatization Sequences Catalyzed by Nanostructured Iron(III)‐Porphyrin Complex towards Benzoxazole Derivatives

“…2-substituted benzoxazole derivatives in recent years. [17][18][19] In this regard, numerous synthetic protocols for 2-substituted benzoxazole derivatives have been described in the literature (Figure 2). [20][21][22][23][24][25][26][27][28][29][30][31][32] While the strategies as mentioned above enriched approaches to 2-substituted benzoxazole derivatives, their applicability is often compromised by the use of expensive metals, utilization of harsh reaction conditions, high catalyst loading, and use of volatile and toxic organic solvents.…”

“…Furthermore, there is a remarkable interest to develop new strategies for the efficient and more applicable synthesis of 2‐substituted benzoxazole derivatives in recent years . In this regard, numerous synthetic protocols for 2‐substituted benzoxazole derivatives have been described in the literature (Figure ) …”

Progress in Synthesis of 2-Substituted Benzothiazole Compounds

“…2-氨基苯硫酚与羰基衍生物的缩合反应, 是构 建 2-取代苯并噻唑常用的方法. 董志兵等 [9] 详细报道了 2-氨基苯硫酚与各种羰基试剂进行多米诺缩合/环化反 Electron transfer 图式 1 2-氨基苯硫酚与醛的反应机理 Scheme 1 Reaction mechanism of 2-aminothiophenol with aldehydes 1.1 缩合反应 1.1.1 邻氨基苯硫酚和醛的缩合 2014 年, 王桦课题组 [10] 合成了一种非均相有机催 化剂介孔聚(三聚氰胺-甲醛), 其在氧气存在下可以催 化各种醛与 2-氨基苯酚缩合形成 2-取代苯并噻唑衍生 物. 该催化剂在该反应中重复使用 6 次以上不丧失催化 活性(Scheme 2, Method 1).…”