Hydroxy‐ and Aminophenyl Radicals from Arenediazonium Salts

Abstract

A buried polar bilayer interface composed of interdigitated peptide ends and a high density of CF3COO− counterions passifying lysine amines are identified in nanotubes obtained by self‐assembly of short peptides. The structure reveals distinct characteristics that differentiate peptide bilayers and lipid bilayers that can now be exploited for the construction of lipid‐like nanomaterials with protein functionality.

Ru‐ and Pd‐Catalysed Synthesis of 2‐Arylfurans by One‐Flask Heck Arylation/Oxidation

“…For certain substrates, the Ti III -mediated arylation of furans with diazonium salts might have potential as a useful alternative. [14] It has been reported, though, that Meerwein-type arylation reactions cannot be applied to the synthesis of 2,5-diarylfurans such as 6 or 9, [7] which have instead been synthesized from symmetrical 2,5-distannylfurans [15] in double Stille couplings. The disadvantages of this method include potential contamination of the products with organostannane residues, as well as selectivity issues arising when the method is adopted for the synthesis of unsymmetrical 2,5-diarylfurans.…”

Radical electrophilicities in solvent

“…This scale, based on the electrophilicity index as introduced by Parr et al [2] (for a recent review see Chattaraj et al [3]) and defined as the electronic chemical potential squared over two times the chemical hardness, has proven its value since assisting in classifying radical systems [4][5][6][7][8][9][10], explaining reaction behavior and introducing other chemical concepts like radical stability [11][12][13][14]. The question arises, though, as to whether the order of this gas-phase electrophilicity scale still holds for radicals in solution.…”

How the Structural Elucidation of the Natural Product Stephanosporin Led to New Developments in Aryl Radical and Medicinal Chemistry

“…117 This study on the previously rarely examined 2-and 4-hydroxyphenyldiazonium ions demonstrated that the related 2-and 4-hydroxyphenyl radicals also show exceptional behaviors in biphasic reaction mixtures. Apparently as a result of their high polarity, these radicals react preferentially in the aqueous phase, so that selective arylation of protonated furfurylamine can be achieved in the presence of an equal amount of 2-methylfuran dissolved in cyclohexane.…”

“…117 An analogous experiment with the related 4-hydroxyphenyldiazonium salt provided the corresponding biaryl in 48% yield.…”

“…The fungicides boscalid (115), 124 bixafen (116), 125 and fluxapyroxad (Xemium) (117) (Figure 3), 126 which all contain 2-aminobiphenyls as substructures, are currently manufactured on an industrial scale by procedures that rely on Suzuki-type crosscoupling reactions. Alternative syntheses for two of the three aminobiphenyls used as building blocks for the fungicides are shown in Schemes 33 and 34.…”