I₂-Catalyzed diamination of acetyl-compounds for the synthesis of multi-substituted imidazoles

Abstract

We have successfully developed the I2-catalysed synthesis of substituted imidazole derivatives from amidines and ketones in good to excellent yields and 100% regioselectivity.

Acid‐Acid‐Catalyzed Tandem Reactions Driven by an Additive‐Like Component

“…In this reaction, I 2 served as an additive‐like component to activate the substrate, thus playing the role of the function I (Scheme 16). [38b] Initially, the reaction proceeded through the electrophilic activation of iodine and generated the corresponding iodoacetophenone 44 . Then the tautomer of amidine reacted with 44 to afford an intermediate I56 , which underwent an intramolecular cyclization to furnish the desired product 43 .…”

Direct Access to 1,3,5-Trisubstituted 1H-1,2,4-Triazoles from N-Phenylbenzamidines via Copper-Catalyzed Diamination of Aryl Nitriles

“…Analytical TLC was performed with Merck silica gel 60 F254 plates, and the products were visualized by UV detection. 1 H NMR (300 MHz) and 13 C NMR (75 MHz) spectra were recorded in CDCl 3 on an Agilent Mercury plus 300 BB spectrometer. Chemical shifts (δ) are reported in ppm using TMS as internal standard.…”

“…10 Our group has also reported some facile methods for the preparation of substituted 1,2,3-triazoles by means of copper-catalyzed tandem cyclization. 11 Additionally, we discovered certain diamination processes of aldehydes, 12 as well as acetyl compounds, 13 to form different imidazole skeletons. Herein, we report the synthesis of 1,3,5-trisubstituted 1H-1,2,4-triazoles from readily available N-phenylbenzamidines and aryl nitriles.…”

An Efficient Synthesis of 1,2,4-Trisubstituted Imidazoles from Arylacetic Acids andN-Arylbenzamidines via Simultaneous C-H and N-H Bond Activation

“…Amidines have been widely employed precursors due to their easy availability and ability to furnish multisubstituted imidazoles via (3+2) cycloaddition reaction or radical pathway. In this context, Bao‐hua Chen and co‐workers reported iodine‐zinc iodide catalyzed process from acetophenones and I 2 ‐catalyzed [3+1+1] cycloaddition from aldehydes to form imidazoles. Iron catalyzed three‐component reaction was established by using aldehydes, amidines and nitroalkanes, while (3+2) cycloaddition of nitrovinylbenzene was accomplished by using copper iodide .…”