CuCl2-catalyzed N O bond cleavage of oxime esters: Approach to imidazoheterocycles and furo[3,2-c]chromenyl fused imidazoles
作者:Santosh K. Gudimella、Amanpreet Kaur、Ram Kumar、Sampak Samanta
DOI:10.1016/j.tetlet.2020.152147
日期:2020.7
An articulate approach to a diverse set of imidazoheterocycles in good to high yields via a copper-catalyzed aza-annulation of several oxime esters with a group of 2-amino-azaarenes was developed. The above cyclization reaction probably proceeds via a single electron transfer process which embodies a new technique for creating two new CN bonds for imidazole ring synthesis. Gratifyingly, the implementation
通过用几种肟酯与一组2-氨基氮杂氮杂铜进行铜催化的氮杂环化反应,开发了一种以良好至高收率的多种咪唑杂环杂环的铰接方法。上述环化反应可能是通过单电子转移过程进行的,这体现了一种新技术,该技术为咪唑环合成生成两个新的C N键。令人欣慰的是,该化学方法的实施可以进一步扩展为通过连续的C N键形成,合成带有呋喃[3,2- c ]亚甲基部分的新型稠合咪唑,随后是C(sp 2)-H功能化/ 5-内切-乙氧基环化(CC和C在铜(II)作为π亲电Lewis酸催化剂的情况下,原位生成带有环状烯酮的稠合咪唑。
Direct Synthesis of Functional Azaxanthones by Using a Domino Three-Component Reaction
作者:Jianwei Yan、Ming Cheng、Feng Hu、Youhong Hu
DOI:10.1021/ol3013099
日期:2012.6.15
NH aldimines, generated in situ from the corresponding aldehydes by reaction with ammonium acetate, serve as nitrogen nucleophiles in reactions with 3-(1-alkynyl)chromones and 3-cyanochromones that generate functionalized azaxanthones. These processes take place under mild conditions that do not require dry solvents. The products of the reactions described represent new chemical entities. We believe that the newly developed cascade process will serve as a potent method for the synthesis of N-heterocycles and in diversity-oriented synthesis.
Synthesis of novel functional polycyclic chromones through Michael addition and double cyclizations
作者:Yang Liu、Liping Huang、Fuchun Xie、Xuxing Chen、Youhong Hu
DOI:10.1039/c0ob01000f
日期:——
2-halobenzylic nitriles (esters or amides) for the synthesis of novel functional polycyclic chromenones has been developed. This tandem process involves multiple reactions, such as Michael addition and double cyclizations without a transition metal catalyst.