Synthesis of π‐Functional Molecules through Oxidation of Aromatic Amines

Abstract

In this review,w ef ocus on the synthesiso fp-conjugated functional molecules by the oxidation of aromatic amines, which is one of the most effective methods fort he constructiono fC ÀC, CÀN, and NÀNb onds between two pconjugated molecular units,a nd consider their characteristics and applications. Polyanilines are the most common products of the oxidation of aromatic amines;h owever,a zobenzenes, phenazines, and 1,1'-binaphthyl-2,2'-diaminesm ay be produced in this manner also, depending on the reaction conditions. Recent advances in the methodology of aniline oxidation have led to the development of high-regioselectivity industrial-scale syntheses of optically or electroactive pfunctional dyes containing nitrogen atoms. In particular,t he regioselective fusion of p-extended aromatic amines can be used to prepare distorted p-conjugated molecules under mild reactionc onditions, allowing the construction of unprecedented curved nitrogen-containing p-conjugated molecules.Scheme1.Aniline oxidations.Scheme2.Reactionpathways for aniline oxidation.[a] Prof.

Phenanthrene-Extended Phenazine Dication: An Electrochromic Conformational Switch Presenting Dual Reactivity

“…Given the electron-rich nature of 1 and, particularly, of position 10 on the phenanthrene system, obtaining the desired reaction using air as the oxidant seemed a rather convenient option, especially considering that different C–N bond formation reactions involving air (or O 2 ) and bases (such as KOtBu) are reported in the literature. 45 This presents two clear advantages: (i) it allows to generate a complex molecular structure starting from commercially available precursors in a single step and (ii) it avoids the addition of other reagents exploiting the presence of NaOtBu used in the cross-coupling step. At this point, the synthesis started with Buchwald–Hartwig coupling between 9-bromophenanthrene and 4- t Bu aniline, resulting in the quantitative formation of 1 after only 1 h ( Scheme 1 ).…”

Color Control in Bis-ethylenedioxythiophene Phenylene Anodically Coloring Electrochromes

“…The most electron-rich chromophore BEDOT-DAB with the amino substituent has the lowest E ox peak at 0.03 V vs Fc/Fc + due to strong electron donation effects of the amino substituent. However, the DPV technique is complicated by exhibiting four peaks that are unstable and change during subsequent cyclic runs, which are likely attributed to the additional formation of the amino radical that is highly reactive. − BEDOT-DMOB has the next lowest E ox at 0.16 V because of the strong donating effects of the methoxy into the ring, making it electron rich, coupled with a low energy barrier to planarity. We continue to shift the E ox to more positive potential by incorporating an unsubstituted BEDOT-B and BEDOT-DFB, therefore attaining 0.32 and 0.43 V, respectively.…”

Unique Pseudo-Cross-Conjugated Mesomeric Betaines via an Iodate-Promoted Reaction of 3,3-Difluorocyclopropenes, Pyridines, and Anilines

“…However, it would not be right to consider an aerobic pathway of the 41 → 87 step since, in general, the oxidation mechanism and the reaction outcome strongly depend on the nature of the oxidant and media. Anilines and indolizin-1-ols are both prone to oxidation, and initially, we did not exclude the possibility of the nitrenium cation ArNH + or nitrene ArN participation, which could interact with the nucleophilic indolizin-1-ol 41 . In the experiment (entry 5), we found that the preformed 41 undergoes immediate oxidative dimerization upon addition of NaIO 3 in nonacidic media.…”