On the Role of Nitrogen Monoxide (Nitric Oxide) in the Nitration of a Tyrosine Derivative and Model Compounds

Abstract

The nitration of tyrosine derivatives with nitrogen monoxide (nitric oxide) occurs only in the presence of dioxygen, and the hypothesized mechanism involves nitrogen dioxide (·NO2). For better understanding of the reaction mechanism, the nitration of model compounds − such as 1‐ and 2‐naphthols and their corresponding 2‐ and 1‐nitroso derivatives − with nitrogen monoxide in the presence and in the absence of dioxygen was studied. The results described here show that tyrosine and naphthols do not undergo nitrosation when they react with ·NO, and so nitrosation of tyrosine in biological systems is highly unlikely. In addition, the oxidation of nitrosonaphthols ←⇄ isonitrosonaphthols by nitric oxide and its derivatives to the corresponding nitro derivatives does not involve the oxoammonium ion, as reported previously. The mechanistic proposals are supported mainly by ESR investigation and electrochemical data. (© Wiley‐VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)

Reaction of indolinonic aminoxyls with nitric oxide

“…Other studies performed recently by our group on the interaction of nitric oxide with naphthols in the presence or absence of oxygen, showed that there is no reaction when oxygen is absent, whereas in its presence, high yields of nitronaphthols are obtained. 20 In addition, the results obtained are interesting from the antioxidant perspective of these indolinonic aminoxyls. Several studies have now highlighted the excellent…”

“…int.) 372 (M ϩ , 2), 342 (100), 326 (20), 266 (89); HRMS calcd. for C 21 H 16 N 4 O 3 372.1222, found 372.1215.…”

Selective aerobic oxidation of hydroxy compounds catalyzed by photoactivated ruthenium‐salen complexes (selective catalytic aerobic oxidation)

“…While several diastereoselective oxygen radical cyclizations have been developed for the synthesis of optically active cyclic ethers, few enantioselective methods have been reported. In biological system, oxidative dimerization of phenolic substrates is known to proceed with complete enantioselectivity 35. Significantly, Ferringa and Wynberg for the first time achieved a bioinspired oxygen radical cyclization of phenol derivatives using a stoichiometric quantity of chiral copper‐diamine complexes, albeit with low enantioselectivity (∼1.3% ee) 32c.…”

The Slow Rearrangement of a Sterically Hindered Nitro‐Cyclohexadienone and the Absence of Phenol Oxidation by Nitrogen Monoxide

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