Silver‐Promoted [3+1+1] Annulation of Isocyanoacetates with Nitrosoarenes

Abstract

3+ +1+ +1] annulation of isocyanoacetates with nitrosoarenes for the preparation of 1,4,5-trisubstituted imidazoles or 4,5-dihydro-1H-imidazoles has been disclosed. Isocyanoacetates serve as both at hree-atom component and ao ne-carbonu nit in the reaction. Specially, with catalytic amounts of Ag 2 CO 3 and ar educed temperature this [3+ +1+ +1] annulation of isocyanoacetates enablest he formation of trans-imidazolines in good yield and with high diastereoselectivity.S ilver plays ac ritical dual role:i )ast he catalyst for the efficiency to activate the isocyanides and ii)the oxidantina romatization process.

Recent Advances in the Synthesis of Imidazolines (2009–2020)

“…In 2018, Fang et al reported an example of a silvermediated [3 + 1 + 1] annulation of isocyanoacetate (202) with nitrosoarene (201) to synthesize 2-imidazoline (Scheme 57). [64] The reaction was performed by reacting nitrosobenzene (201) with isocyanoacetate (202) in the presence of Ag 2 CO 3 (10 mol%) at 30°C, and the trans-imidazoline (203) was isolated in 55% yield. The article was focused on the synthesis of imidazole (204) in the presence of a silver catalyst and a base.…”

Green and rapid and instrumental one-pot method for the synthesis of imidazolines having potential anti-SARS-CoV-2 main protease activity

“…These conditions included the asymmetric [3 + 2]-cycloaddition reaction of chiral N -phosphonyl imines with methyl iso-cyanoacetate in a nonpolar medium at room temperature ( Bagherzade et al, 2021 ; Qiao et al, 2017 ; Bakhshi et al, 2021 ). Silver salts have been utilized as catalysts along with DBU as a base in an efficient catalytic system for the [3 + 1+1] annulation of iso-cyanoacetate with nitroarene as demonstrated by Fang et al (2018) . However, DBU is an expensive base for synthesizing derivatives of 2-imidazolines.…”