A New Method for the Synthesis of Imidazolidinone- and Benzimidazolone-Containing [2.2]Cyclophanes

Abstract

A novel acid-catalyzed double nucleophilic addition of bisthiols to heterocyclic bisacetals gives sulfur-containing macrocycles in good yield. Crossover experiments revealed that the acid-catalyzed N-acyl iminium cyclization for the imidazolidinones is reversible. The sulfur atom in the bridge was extruded photochemically, giving new [2.2]heterophanes containing the imidazolidinone and benzimidazolone ring systems. The determined crystal structures for representative members in the benzimidazolone series are also reported.

Synthesis of polymethyl substituted [2.2]metaparacyclophanes and their Lewis-acid induced isomerisation to [2.2]metacyclophanes

“…18 The cyclisation of bis(chloromethyl) benzenes 4a and 4b and bis(sulfanylmethyl)benzene 6 was carried out under highly diluted conditions in 10% ethanolic KOH in the presence of a small amount of NaBH 4 , giving the desired 2,11-dithia [3.3]MPCPs 7a and 7b in good yield. Photolysis of 7a and 7b with a high-pressure murcury lamp (400W) in triethylphosphate was carried out according to the reported method 19,20 to afford the corresponding [2.2]MPCPs 8a and 8b in good yields, respectively. The structures of 8a and 8b were determined on the basis of their elemental analyses and spectral data.…”

Diaquabis[2-(5-isopropyl-5-methyl-4-oxo-4,5-dihydro-1H-imidazol-2-yl)nicotinato]cobalt(II)

“…Much effort has been devoted to the synthesis (Bombek et al, 2005;Ellis et al, 2000) and crystal structures (Erre et al, 1998;Fu et al, 2008) of the compounds containing imidazolidinone derivatives during the last few years. One of them is (±)-2-(4-isopropyl-4-methyl-5-oxo-4,5-dihydro-1H-2-imidazol-2-yl) nicotinic acid (Imazapyr acid), which provides efficient metal-chelating ability.…”

Bi(OTf)3‐Catalysed Access to 2,3‐Substituted Isoindolinones and Tricyclic N,O‐Acetals by Trapping of Bis‐N‐Acyliminium Species in a Tandem Process

“…[6b], [6c] The latter group belongs to the class of natural products referred to as epidithiodiketopiperazines (ETPs); the ETPs command a good deal of importance for their redox properties. The 1,5‐bis‐electrophiles in the imidazolidinone and benzimidazolidinone areas for their part, were embarked in the first synthesis of cyclophanes via corresponding dithiacyclophanes (Figure ) . The importance of these findings undoubtedly increases the attractiveness of this chemistry, especially when the target molecules have notable biological activities and their production may or may not be accompanied with environmentally weak effects.…”