Copper(II)-Mediated Iodination of 1-Nitroso-2-naphthol.

Zarina M Efimenko,Nadezhda A Bokach,Vadim Yu Kukushkin,Vitalii V Suslonov,Maxim L Kuznetsov,Anton V Rozhkov

doi:10.3390/molecules26185708

Zarina M Efimenko, Nadezhda A Bokach + Show 4 more

Open Access

https://doi.org/10.3390/molecules26185708

Copy DOI

Abstract

The 3-Iodo-1-nitrosonaphthalene-2-ol (I-NON) was obtained by the copper(II)-mediated iodination of 1-nitroso-2-naphthol (NON). The suitable reactants and optimized reaction conditions, providing 94% NMR yield of I-NON, included the usage of Cu(OAc)2·H2O and 1:2:8 CuII/NON/I2 molar ratio between the reactants. The obtained I-NON was characterized by elemental analyses (C, H, N), high-resolution ESI+-MS, 1H and 13C{1H} NMR, FTIR, UV-vis spectroscopy, TGA, and X-ray crystallography (XRD). The copper(II) complexes bearing deprotonated I-NON were prepared as follows: cis-[Cu(I-NON–H)(I-NON)](I3) (1) was obtained by the reaction between Cu(NON-H)2 and I2 in CHCl3/MeOH, while trans-[Cu(I-NON–H)2] (2) was synthesized from I-NON and Cu(OAc)2 in MeOH. Crystals of trans-[Cu(I-NON–H)2(THF)2] (3) and trans-[Cu(I-NON–H)2(Py)2] (4) were precipitated from solutions of 2 in CHCl3/THF and Py/CHCl3/MeOH mixtures, respectively. The structures of 1 and 3–4 were additionally verified by X-ray crystallography. The characteristic feature of the structures of 1 and 3 is the presence of intermolecular halogen bonds with the involvement of the iodine center of the metal-bound deprotonated I-NON. The nature of the I···I and I···O contacts in the structures of 1 and 3, correspondingly, were studied theoretically at the DFT (PBE0-D3BJ) level using the QTAIM, ESP, ELF, NBO, and IGM methods.

Highlights

Nitrosonaphthols, typically existing in the quinone monoxime tautomeric form [1], represent a group of compounds that found a wide range of useful applications
These species have been applied as precursors in organic synthesis [2], they were used for the analytical determination of bioorganic species [3,4], and they exhibit some biological activity modes as iminoxyl and hydronitroxide radical source [5]
The electrostatic potential (ESP), electron localization function (ELF), and natural bond orbital (NBO) analyses clearly indicate that this bond is of type II with the I2 atom serving as an halogen bond (HaB) donor

Summary

Introduction

Nitrosonaphthols, typically existing in the quinone monoxime tautomeric form (see ESI, Scheme S1) [1], represent a group of compounds that found a wide range of useful applications. These species have been applied as precursors in organic synthesis [2], they were used for the analytical determination of bioorganic species [3,4], and they exhibit some biological activity modes (e.g., carcinogenic) as iminoxyl and hydronitroxide radical source [5]. 1 was crystallized directly from the reaction mixture Structures of these three complexes were studied by XRD (Figures 2–4, Table 2). The Cu1–I4 distance (3.59 Å) is greater than the corresponding sum of Bondi van der Waals radii [33,34] (3.38 Å), but is still substantially smaller than sum of Batsanov crystallographic van der Waals radii (4.1 Å) [35], and, the Cu1–I4 linkage can be attributed to the semicoordination bond [32]

Halogen Bonding Interactions Involving Ligated I-NON

Materials and Methods

X-ray Structure Determinations

Synthetic Work

Findings

Computational Details