Direct synthesis of 2,4,5-trisubstituted imidazoles and di/tri-substituted pyrimidines via cycloadditions of α,β-unsaturated ketones/aldehydes and N′-hydroxyl imidamides
作者:Ping Wu、Xueguo Zhang、Baohua Chen
DOI:10.1016/j.tetlet.2019.03.025
日期:2019.4
di/trisubstituted pyrimidines via iron-catalyzed cross-dehydrogenative coupling (CDC), with excellent tolerance and yields, has been developed. In this report, α,β-unsaturatedaldehydes/ketones and N′-hydroxyl imidamides undergo [3+2] and [3+3] cycloadditions in two processes, involving iron-mediated Michael reaction, Robinson Annulation and 1,5-electrocyclization.
Bioinspired Radical‐Mediated Transition‐Metal‐Free Synthesis of N‐Heterocycles under Visible Light
作者:Amreen K. Bains、Yadav Ankit、Debashis Adhikari
DOI:10.1002/cssc.202002161
日期:2021.1.7
extended to multi‐component, one‐pot coupling for the synthesis of quinoline and pyrimidine. This organocatalytic approach is very mild (70 °C, 8 h) compared to a multitude of transition‐metal catalysts that have been used to prepare these heterocycles. A detailed mechanistic study proves the intermediacy of the iminosemiquinonate‐type radical and a critical hydrogen atom transfer step to be involved
Iron-Catalyzed Alkyne-Based Multicomponent Synthesis of Pyrimidines under Air
作者:Rakesh Mondal、Gargi Chakraborty、Amit Kumar Guin、Susmita Sarkar、Nanda D. Paul
DOI:10.1021/acs.joc.1c00867
日期:2021.10.1
An iron-catalyzed sustainable, economically affordable, and eco-friendly synthetic protocol for the construction of various trisubstitutedpyrimidines is described. A wide range of trisubstitutedpyrimidines were prepared using a well-defined, easy to prepare, bench-stable, and phosphine-free iron catalyst featuring a redox-noninnocent tridentate arylazo pincer under comparatively mild aerobic conditions