Synthesis of Hydrobenzoimidazoles from para‐Quinamines and 1,3,5‐Triazinanes via a Formal [3+2] Annulation Reaction

Abstract

The synthesis of hydrobenzoimidazoles from para‐quinamines and 1,3,5‐triazinanes was achieved via a formal [3+2] annulation reaction in the presence of In(OTf)3 as the catalyst. Further studies demonstrated that the synthesis of hydrobenzooxazoles could also be accomplished via the same strategy from para‐quinols and 1,3,5‐triazinanes.

Research Progress of 1,3,5-Triazinanes in the Synthesis of Nitrogen-Containing Heterocycles

“…考虑到咪唑啉骨架在药物化学中的重要 性, 作者随机选择了部分由该方法合成的咪唑啉产物, 用于评估人类不同癌细胞系中的抗增殖活性, 初步结果 表明, 这些咪唑啉类化合物对人类许多癌细胞显示出有 希望的抗肿瘤活性, 可作为抗肿瘤研究的热门化合物. 翟宏斌等 [21] 孙江涛等 [22] 报道了一种碱促进合成咪唑啉酮的方 法(Scheme 8). 该方法不需要使用过渡金属催化剂, 反 应过程中, 现场产生氮杂烯丙基正离子 23 和甲酰基苯 基亚胺 24 两种活性中间体, 这两种中间体随后进行分 子间[2＋3]环加成反应, 一锅法合成咪唑啉酮衍生物.…”

“…(2) 1,3,5-三嗪烷产生甲酰基亚胺中间体. 与刘 吉开课题组 [21] 相比, 该方法具有反应时间短, 底物适用 同年, 宣俊等 [27] 报道了一种合成 1,3-苯并噁嗪衍生 物的方法(Scheme 13). 反应无需添加过渡金属催化剂、 翟宏斌课题组 [28] 发展了一种合成苯并呋喃并嘧啶 衍生物的方法(Scheme 2021 年, 宣俊课题组 [29] 报道了一种光催化 α-重氮 酸酯合成氮杂环丙烷的方法(图示 15).…”

Electrochemical formal [3 + 2] cycloaddition of azobenzenes with hexahydro-1,3,5-triazines

“…10 Generally, 1,3,5-triazinanes serving as electrophilic reagents are broadly used in various aminomethylation 11 and cycloaddition reactions. 12 Particularly, 1,3,5-triazinanes acting as two-, three-, four-, and six-atom synthons in diverse cycloaddition reactions have been established for the construction of heterocycles. 10,12 Considering the application of hexahydro-1,3,5-triazines in synthetic chemistry, we speculate that electrochemistry might prove useful in the functionalization of azobenzenes with hexahydro-1,3,5-triazines as cyclization reagents.…”

Chiral Phosphoric Acid Catalyzed Asymmetric Desymmetrization of para-Quinamines with Isocyanates: Access to Functionalized Imidazolidin-2-one Derivatives

“…Among the reported substrate class, para -quinamines have attracted considerable attention in chemical community because such reactants could be supposed as a novel three-atom synthon to furnish nitrogen-containing heterocyclic ring systems . However, most of the desymmetrization of para -quinamines via annulation reactions are [3 + 2] and [3 + 3] cyclization in racemic manner. , The enantioselective desymmetrization of para -quinamines were rarely reported (Scheme a).…”