Volume 82, Issue 4

The 13th International Symposium on Novel Aromatic Compounds (ISNA-13) was held in Luxembourg City, Grand-Duchy of Luxembourg, the smallest country so far hosting a conference of the ISNA series. It took place 19-24 July 2009 and was attended by 360 participants, mostly from academic institutions, representing 34 countries. The scientific program consisted of the Opening Plenary Lecture given by Prof. Jean-Marie Lehn (Institute of Science and Supramolecular Engineering and Louis Pasteur University, Strasbourg), the 2009 Nozoe Lecture presented by Prof. Atsuhiro Osuka (Kyoto University, Kyoto), 34 invited lectures, 26 oral communications, and 194 posters presented in two sessions. In a public lecture, vice rector Prof. Luciënne Blessing presented the activities of the recently founded University of Luxembourg. The organizing committee made a strong and successful effort to attract numerous graduate and undergraduate students to ISNA-13. The ISNA symposium series was launched by Prof. Tetsuo Nozoe in 1970 as the International Symposium on Nonbenzenoid Aromatic Compounds. Since then, the currently biennial conference rotates between Asia, North America, and Europe. As indicated by its present name, the focus of the symposium has broadened and is now set on new experimental and theoretical insights into the concept of aromaticity, synthesis and properties of novel aromatic compounds, as well as applications of π-conjugated systems in different fields of molecular science and technology. From a broader perspective, through interactions between participating scientists, ISNA conferences aim at the generation of new knowledge and its eventual application for the betterment of society. In line with the above, the organizers of ISNA-13 emphasized not only the traditional and fundamental aspects of novel aromatic compounds, such as their theory, synthesis, structure, and properties, but also their application in materials science. This included, for example, macrocycles, oligomers, and polymers and their optoelectronic properties, supramolecular chemistry based on aromatic functional modules, aromatics on surfaces, and molecular electronics based on aromatic units. The main subjects of the meeting that are covered in this Special Topic issue are as follows: - aromaticity and novel aromatic systems - theory - aromaticity and novel aromatic systems - experimental - fullerenes and concave aromatics - aromatic polymers and oligomers and their optoelectronic properties - supramolecular aromatic devices, switches, and machines - aromatics on surfaces, including graphene - optoelectronics The next conference, ISNA-14, will be chaired by Profs. Michael M. Haley (University of Oregon, Eugene) and Benjamin T. King (University of Nevada, Reno) and will be held in Eugene, OR, USA, 24-29 July 2011. ISNA-15 will be organized by Prof. Ken-Tsung Wong (National Taiwan University) in Taipei, Taiwan. François Diederich A. Dieter Schlüter Carlo Thilgen Conference Editors

It is a pleasure to introduce this issue devoted to the theme of aromaticity, and to comment on some historical considerations and criteria for Special Topic features in Pure and Applied Chemistry (PAC). The core business of the Journal is to publish papers based upon authoritative lectures presented at IUPACsponsored conferences, symposia, and workshops, and to publish IUPAC Recommendations and Technical Reports. Special Topics were originally conceived as a tool to promote new and emerging principles and practice in all branches of chemical sciences, through the medium of works based upon inaugural events or special IUPAC projects. The latter projects were sometimes driven by Divisional or individual initiatives within the Union, but it has come to be recognized that regular IUPAC-sponsored series of international events also offer rich scope for highlighting important advances in specialized subject areas. This is reflected in the recent history of Special Topic issues. The criteria for selection have emerged as timeliness and strong evidence of support and interest from the community of authors and readers. Publication projects arising from the Special Topics initiative generally continue to achieve gratifyingly favorable citation profiles, and thereby support the view that they fulfil an important and distinctive need in current review literature. Proceedings of most events in the International Symposia in Novel Aromatic Compounds (ISNA) series have routinely been published in PAC for some 40 years, and offer convincing evidence of sustained interest in the chemistry and properties of aromatic compounds, and growing interdisciplinary interfaces with materials sciences and nanotechnologies. The series was inaugurated in Sendai, Japan (1970) as an International Symposium on the Chemistry of Nonbenzenoid Aromatic Compounds. After a second meeting four years later, the current, more inclusive series title emerged as a prescient change that heralded astonishing advances in the role of aromaticity in new-age compounds and materials. The early three- to four-year intervals between events have recently diminished to two years, in apparent response to growing topicality and urgency. A case for Special Topic coverage of ISNA-13 is thus persuasively supported by the community that it serves, as well as the strong citation profiles of collections arising from recent events in the series. The passage to publication for this project has been materially supported by enthusiastic authorship cooperation and timely submission of manuscripts, and it is a particular pleasure to pay tribute to the Chair, Prof. François Diederich, and Co-chair, Prof. A. Dieter Schlüter of the Organizing Committee, and for their roles in the compilation of the scientific program and their exceptional devotion in contributing actively to overseeing peer review of the manuscripts. This collection will serve as an overview of current advances and future opportunities in the field of aromatic chemistry, and an enduring and representative record of an outstanding event. James R. Bull Scientific Editor

The synthesis and characterization of various endohedral metallofullerenes and their derivatives are described. The encapsulated metal atoms’ positions and movements were determined using NMR study, X-ray crystallographic analysis, and theoretical calculations. The results of electrochemical investigations clarified the relation between the electronic properties and the π-electron systems of the fullerene endohedrals.

Generalization of the Hückel rule predicts that the (anti)aromaticity of a neutral ring is qualitatively reverted upon a single twist of the π-orbital array (Möbius interconversion), and is preserved upon expansion of all the bonds by single C 2 units (ring carbo- merization). These opposite effects are addressed from quantitative theoretical and experimental standpoints, respectively. (i) According to most resonance energy (RE) schemes, the RE value of a Möbius ring is not the opposite of that of the Hückel version. This also applies to the Aihara’s and Trinajstic’s topological resonance energy (TRE), where a non-aromatic reference in the topological limit is defined as being “as identical as possible” to the parent ring but just “acyclic”. In spite of its conceptual merits, the computing complexity and fictitious character of the TRE acyclic reference resulted in a disuse of TRE as a current energetic aromaticity index. Both the calculation and interpretation of TRE have been revisited in light of a cross-reference between the Hückel and Möbius rings within the Hückel molecular orbital (HMO) framework. Whereas the topological influence of triple bonds is currently neglected in the first-level HMO treatment of π-conjugated systems, a graph-theoretical analysis allows one to differentiate the TRE value of a [3 n ]annulene from those of the corresponding carbo -[ n ]annulene. The C 18 ring of carbo- benzene is thus predicted to be slightly more topologically aromatic than that of [18]annulene. (ii) Recent experimental and density functional theory (DFT) theoretical studies of quadrupolar carbo -benzene derivatives are presented. The results show that the “flexible aromaticity” of the p- C 18 Ph 4 bridge between donor anisyl substituents plays a crucial role in determining the intriguing chemical/spectroscopical/optical properties of these carbo -chromophores.

The hydroarylation of alkynes (also known as arylation of alkynes or alkenylation of arenes) catalyzed by gold or other electrophilic metal salts or complexes is reviewed from synthetic and mechanistic perspectives.

Shape-persistent macrocycles based on the arylene-ethynylene backbone are synthetically challenging targets that can be obtained in good to high yields either by statistical or by template-supported oxidative Glaser coupling of the corresponding bisacetylenes. The macrocycles can be adsorbed on highly oriented pyrolytic graphite (HOPG) to form well-ordered monolayers as visualized by scanning tunneling microscopy (STM). Moreover, bithiophene-containing macrocycles are able to bind fullerenes at the electron-rich sites of the rings. One-dimensional tubular structures based on shape-persistent macrocycles can also be obtained by oxidative acetylene coupling. These contain intraannularly bound conjugated polymers and represent bichromophoric systems that allow an accumulation of excitation energy on the conjugated core. In the field of defined 2D objects we describe molecular spoked wheels with a lateral expansion of more than 5 nm. These compounds are highly rigid. In order to provide sufficient solubility, they contain peripheral substituents and additional substituents orthogonal to the plane of the molecules.

Fully conjugated π-expanded macrocyclic oligothiophenes with 24π to 180π electron systems have been synthesized using a modified McMurry coupling reaction as the key step. For the synthesis of cyclo[ n ](2,5-thienylene-ethynylene)s composed of thiophenes and acetylenes, bromination-dehydrobromination and double elimination procedure were employed. X-ray analyses of macrocyclic oligothiophenes with 24π, 60π, and 72π systems revealed unique molecular and packing structures, reflecting planar cyclic frameworks with medium to large inner cavities. All the giant macrocycles exhibit multistep reversible redox behavior with a fairly low first-oxidation potentials, reflecting their cyclic conjugation. The doping of macrocycles with iodine forms semiconductors owing to their π-donor properties and π–π stacking ability. Interestingly, 90π, 108π, and 120π systems self-aggregate in the solid state to form red nanofibers or petal structure, whereas 150π to 180π systems form red nanoparticles. The structures of fibrous aggregates and particles have been established by scanning electron microscopy (SEM) and atomic force microscopy (AFM) analyses. Furthermore, two-photon properties of 72π, 108π, 144π, and 180π systems show that the increasing π-conjugation leads to an increase in the two-photon absorption cross-section with magnitudes as high as 100 000 GM in the visible spectral region.

Molecular photoswiches are important for the development of advanced materials and molecular electronics devices. The dihydroazulene (DHA) is a particularly attractive molecule as it undergoes a light-induced ring opening to a vinylheptafulvene (VHF) isomer with altered optical properties. While functionalization of the five-membered ring of DHA has been possible for the last 25 years, this was not the case for the seven-membered ring. This article summarizes our synthetic efforts in achieving this goal. Incorporation of an alkyne at C-7 was accomplished by (i) regioselective bromination of DHA, followed by (ii) elimination of HBr, and (iii) Pd-catalyzed cross-coupling with triisopropylsilylacetylene. Light-induced ring opening of this DHA followed by thermal ring closure provided a mixture of 6- and 7-substituted DHAs with different absorption characteristics. The isomer ratio was controlled by the wavelength of irradiation and the solvent polarity. The dibromide formed in the initial step served as a precursor for a 3-bromo-functionalized azulene that was employed as a building block for acetylenic scaffolding. Incorporation of a dithiafulvene (DTF) unit at the five-membered ring of DHA resulted in a significant red-shift in the longest-wavelength absorption and consequently a lowering of the energy required for ring opening. Incorporation of a redox-active tetrathiafulvalene (TTF) unit allowed for redox-controlled photoswitching.

Carbon nanotubes (CNTs) can be functionalized using a variety of efficient protocols. Especially, esterification and amidation reactions are exploited along with 1,3-dipolar cycloadditions. The use of microwaves (MWs) to activate the reactivity of CNTs is also reported. Innovative NMR methodologies can be introduced to investigate the covalent attachment of organic moieties to CNTs.

Tetraphenylethene (TPE)-substitued silanes [(Ph 4 C=C) m Si(Ph) n , m = 3–1, n = 3–1] are designed and synthesized, and their optical, thermal, and electrochemical properties are studied. Whereas they are nonluminescent in solutions, they become highly emissive when aggregated in poor solvents (such as water) or fabricated into thin films, demonstrating a novel phenomenon of aggregation-induced emission (AIE). Their amorphous films exhibit high fluorescence quantum yields (54.6–63.7 %). They enjoy high thermal stability with 5 % weight loss occurring at 320–420 °C. Multilayer electroluminescence (EL) devices (ITO/NPB/emitter/TPBi/LiF/Al) utilizing the silanes as emitting layers are fabricated, which give deep blue EL with maximum luminance and external quantum efficiency of 5672 cd/m 2 , and 1.6 %, respectively.

The synthesis and structural characterization of a hitherto unknown tetradehydro-dinaphtho[10]annulene, which had eluded isolation since attempts initiated during the late 1960s, was achieved. Moreover, the dehydroannulene was transformed into stable derivatives of zethrene, which was first reported in 1955, but forgotten for a long time. These molecules are substituted at the 7,14-positions and open the door to the zethrene family for potential application as optoelectronic materials.

Novel hydrido(silacyclohexadienyl)chromium complexes bearing a bulky substituent, Tbt (2,4,6-tris[bis(trimethylsilyl)methyl]phenyl), were synthesized using formal insertion reactions of Cr(0) into C–H or Si–H bond. When the reactions of 1-silacyclohexa-2,4-dienes bearing a hydroxy or chloro group on the silicon atom with [Cr(CH 3 CN) 3 (CO) 3 ] were performed, the corresponding hydrido(1-silacyclohexa-2,4-dienyl) complexes were obtained as the sole product. A similar reaction of a hydrosilane having a similar skeleton with [Cr(CH 3 CN) 3 (CO) 3 ] gave an unprecedented type of silacyclohexadienyl complex, hydrido(1-silacyclohexa-1,3-dienyl)chromium bearing a three-center bonding interaction among the silicon, hydrogen, and chromium atoms. These are the first syntheses of silacyclohexadienyl complexes by the formal insertion reaction toward the corresponding silacyclohexadienes. Furthermore, the isolation of the silacyclohexadienyl anion was achieved; it was applied to synthesis of the corresponding sandwich-type iron complex. Structures of the newly obtained complexes were revealed based on their NMR and IR spectroscopic data and X-ray diffraction study.

Molecules composed of sp-hybridized carbon chains (polyynes) are the simplest of the known conjugated organic oligomers. In comparison to their counterparts such as polyacetylene and polydiacetylene, however, the formation of polyynes has traditionally posed a difficult synthetic challenge. In particular, there is no reliable method to form end-capped polyethynylene, and monodisperse polyynes have therefore been assembled. As a result, structure–property relationships for shorter polyynes have been relatively well established in recent years, while extension of these trends toward longer polyynes has remained a difficult task. Using the Fritsch–Buttenberg–Wiechell (FBW) rearrangement, the formation of diynes through decaynes has become possible and has provided a unique chance to explore the physical characteristics of conjugated polyyne chains. This paper highlights recent advances in the synthesis of extended polyynes, as well as interesting aspects of their NMR, Raman, and UV/vis spectroscopic analyses. These synthetic achievements offer the opportunity to predict some of the properties of the carbon allotrope carbyne. In particular, a set of X-ray crystallographic analyses of t -Bu end-capped polyynes ( tBu[ n ] ) shows a definitive experimental trend in reduced bond-length alternation (BLA).

The hypothetical polymer obtained by linear annelation of benzene units, polyacene (PAC) (C 4 H 2 ) n , has received considerable attention over the last 50 years. This interest is due to the unusual electronic structure that is assumed to result in usual physical properties. The review summarizes the theoretical investigations of PAC research. The most recent computational analyses available in the literature are based on density functional theory (DFT) for PAC and on the complete active space self-consistent field (CASSCF) method for oligoacenes and suggest an undistorted symmetrical structure with an antiferromagnetic (AFM) coupling of electrons.

The controlled engineering of functional architectures composed of π-systems with unusual opto-electronic properties is currently being investigated intensively from both fundamental research and technological application viewpoints. In particular, the exploitation of the supramolecular approach for the facile construction of multidimensional architectures, featuring cavities capable of hosting functional molecules, could be used in several applications, such as nanomedicine, molecular-based memory storage devices, and sensors. This paper highlights our recent strategies to use hydrogen-bonding interactions to prepare nanostructured functional architectures via the self-assembly of organic molecular modules studied at different interfaces.

Chemomechanics is an emerging area at the interface of chemistry, materials science, physics, and biology that aims at quantitative understanding of reaction dynamics in multiscale phenomena. These are characterized by correlated directional motion at multiple length scales—from molecular to macroscopic. Examples include reactions in stressed materials, in shear flows, and at propagating interfaces, the operation of motor proteins, ion pumps, and actuating polymers, and mechanosensing. To explain the up to 10 15 -fold variations in reaction rates in multiscale phenomena—which are incompatible within the standard models of chemical kinetics—chemomechanics relies on the concept of molecular restoring force. Molecular force probes are inert molecules that allow incremental variations in restoring forces of diverse reactive moieties over hundreds of piconewtons (pN). Extending beyond the classical studies of reactions of strained molecules, molecular force probes enable experimental explorations of how reaction rates and restoring forces are related. In this review, we will describe the utility of one such probe—stiff stilbene. Various reactive moieties were incorporated in inert linkers that constrained stiff stilbene to highly strained macrocycles. Such series provided the first direct experimental validation of the most popular chemomechanical model, demonstrated its predictive capabilities, and illustrated the diversity of relationships between reaction rates and forces.

The history and development of pyrazine- and pyridine-type heteroacenes and their use in solid-state organic electronics are discussed and reviewed. The larger N -heteroacenes are potential electron- or hole-transporting materials and should therefore complement acenes in organic electronics. As they feature electronegative nitrogen ring atoms in their molecular skeleton, issues with oxidation should be less problematic when comparing them to the larger acenes such as pentacene. This paper covers the synthesis and the solid-state packing of larger (tetracene/pentacene-based) N , N -heterocylic acenes as well as the question of the interplay of aromaticity and antiaromaticity in the known larger N -heteroacenes and their N , N -dihydro-derivatives; also illuminated are their optical properties. A literature overview is provided. Keywords : acenes; alkynes; heterocycles; organic chemistry; organic electronics.

A theoretical study was conducted on the bowl-to-bowl inversion of sumanene: its benzylic mono-, di-, and trianion species and its mono-, di-, and trinaphthosumanenes. The use of B3LYP/6-311+G(2d,p) for the B3LYP/6-31G(d,p)-optimized geometries approximately reproduced the experimental values for the bowl-to-bowl inversion of sumanene, and its benzylic mono- and dianion species. The value for the trianion was estimated to be around 21 kcal/mol using the above levels. The investigation of naphthosumanenes clearly indicated a noted increase in the inversion barrier with additional fused rings. The calculated inversion barrier for mononaphthosumanene also correctly reproduced the experimental value (32.2 kcal/mol) using the above levels (31.4 kcal/mol). The calculated barrier for trinaphthosumanene reached 63.8 kcal/mol, therefore, the bowl-to-bowl inversion is less likely to occur under realistic conditions.

Alternating meta - and para -phenylene-linked oligoarylamines are considered as promising molecular parts for the molecule-based electronics and/or spintronics due to their intriguing electronic and magnetic properties. From the magnetic viewpoint, a -meta -phenylene linker plays a crucial role in ensuring the effective ferromagnetic interaction, while para -phenylene linker plays an important part in stabilizing the spin-containing aminium radical cations. Of the meta – para and all- meta oligoarylamines prepared so far, the macrocyclic oligoarylamines are structurally defined, and therefore we can employ them as the component pieces to prepare the two- or three-dimensionally structured oligoarylamines. The spin electronic properties of polycationic species generated from two kinds of macrocyclic oligoarylamines, which will be able to be extended into the 2D multi-spin molecular systems, are described on the basis of the pulsed electron spin resonance (ESR) measurements.

The tetramethylene-bridged molecular tweezers bearing lithium methanephosphonate or dilithium phosphate substituents in the central benzene or naphthalene spacer-unit and the dimethylene-bridged clips containing naphthalene or anthracene sidewalls substituted by lithium methanephosphonate, dilithium phosphate, or sodium sulfate groups in the central benzene spacer-unit are water-soluble. The molecular clips having planar naphthalene sidewalls bind flat aromatic guest molecules preferentially, for example, the nicotinamide ring and/or the adenine-unit in the nucleotides NAD(P) + , NMN, or AMP, whereas the benzene-spaced molecular tweezers with their bent sidewalls form stable host–guest complexes with the aliphatic side chains of basic amino acids such as lysine and argenine. The phosphonate-substituted tweezer and the clips having an extended central naphthalene spacer-unit or extended anthracene and benzo[k]fluoranthene sidewalls, respectively, form highly stable self-assembled dimers in aqueous solution, evidently due to non-classical hydrophobic interactions. The phosphate-substituted molecular clip containing naphthalene sidewalls inhibits the enzymatic, ADH-catalyzed ethanol oxidation by binding the cofactor NAD + in a competitive reaction. Surprisingly, tweezer-bearing phosphate substituents in the central benzene spacer-unit are more efficient inhibitors for the ethanol oxidation than the correspondingly substituted naphthalene clip, even though the tweezer does not bind the cofactor NAD + within the limits of detection. The phosphate-substituted naphthalene clip is, however, a highly efficient inhibitor of the enzymatic oxidation of glucose-6-phosphate (G6P) with NADP + catalyzed by glucose-6-phosphate dehydrogenase (G6PD), whereas the phosphonate-substituted clip only functions as an inhibitor by forming a complex with the cofactor. Detailed kinetic, thermodynamic, and computational modeling studies provide insight into the mechanism of these novel enzyme inhibition reactions.

A high-yielding addition reaction between electron-rich alkynes and a small acceptor molecule, tetracyanoethylene (TCNE), was employed as a new click reaction to construct donor–acceptor chromophores in the polymer main chains and side chains. The donor–acceptor alternating conjugated polymers were prepared from the ferrocene-containing poly(aryleneethynylene)s in one step and atom-economic fashion. The energy levels and thermal properties of the aromatic polyamines substituted by electron-rich alkynes as a side chain can be tunable by the amount of the added TCNE. The resulting donor–acceptor-type polymers feature broad charge-transfer (CT) bands in the visible region, potent redox activities, and improved thermal properties.

The structure and stability of a new family of heterocyclic [ n ]circulenes C n N n Y n ( n = 8–10; Y = N, P, As, BF 2 , AlF 2 , GaF 2 ) have been computationally studied using density functional theory (DFT) B3LYP/6-311G* calculations. The geometry of the compounds is determined by the balance of steric factors and effects of aromatic π-electron delocalization depending on the electronegativity of heteroatoms. An increase in the bulkiness of peripheral atoms Y and enlargement of the inner C n cycle leads to the gradual transformation of the bowl-shaped circulene structure (Y = N, BF 2 ) to planar and then saddle-shaped forms (Y = P, As, AlF 2 , GaF 2 ). The calculations performed manifest stabilization of the heteroannulated circulenes ensured by the strong aromatic character of the conjugated five-membered rings fringing the central non-aromatic or antiaromatic [8–10] annulene rings.

Radical-substituted radical cation salts are exotic species that are potentially applicable as spin building blocks for molecular magnets. We recently found that these species, which are derived from a diphenyldihydrophenazine ( DPP ) framework, are stable under aerated conditions at room temperature. Of these species, nitronyl nitroxide ( NN • )-substituted DPP •+ tetrachloroferrate ( NNDPP ••+ · FeCl 4 – ) showed antiferromagnetic interaction at low temperature (<150 K), whereas the tetrabromoferrate salt NNDPP ••+ · FeBr 4 – exhibited a magnetic phase transition at 6.7 K to produce a bulk ferrimagnet. Both salts had very similar molecular structures. The difference in the magnetic properties was ascribed to the difference in molecular packing structures. A significant difference in these two salts was observed at the ( NNDPP ••+ )–( NNDPP ••+ ) intermolecular contact, including the oxygen atom of the nitroxide moiety; NNDPP ••+ ·FeCl 4 – had a serious antiferromagnetic O–O (nitroxide oxygen, 3.02 Å) intermolecular contact, whereas NNDPP ••+ ·FeBr 4 – had a ferromagnetic O–HC (2.53 Å) intermolecular contact.

A series of title carbocations was generated and isolated as stable salts. X-ray analyses revealed a preference for an unsymmetric structure in which the bridging hydrogen is localized on one of the two triarylmethane units. NMR spectroscopy showed a similar preference in solution. The bridging hydrogen fluctuates between the two chromophores in solution, and the energy barrier for the H shift is linearly correlated with the C···C + separation determined by X-ray. According to an extrapolation, the energy barrier should decrease when the C···C + separation is less than 2.7 Å, which suggests a new model for isolable pure organic species with a three-center–two-electron bond.

Nontraditional aromatic molecules hold tremendous promise for the design and realization of advanced materials for organic electronics applications. In this report, we describe recent work with the 10 π-electron methano[10]annulene molecule. We used chemistry established by Vogel and by Neidlein to incorporate this molecule into organic semiconducting polymers and found that they provide for highly delocalized charge carriers upon electrochemical oxidation/doping into conductive materials. Extensions to a variety of annulene-heteroaromatic copolymers will be described along with pertinent optical and electrical characterization data.

The oxidative phenol coupling reaction of phenols with simple methyl substituents can be difficult due to several by-products. Such a challenging substrate is 2,4-dimethyl-phenol. We studied the electrochemical access to the ortho -coupled dehydrodimer. Anodic treatment in a basic electrolyte supports the formation of a molecular tricyclic architecture called Pummerer’s ketone. Employing a two-step sequence involving anodic conversion of 2,4-dimethylphenol to a preliminary substrate and different workup protocols yield exclusively and diastereoselectively polycyclic architectures. The selective ortho -coupling reaction was achieved by two strategies: A tetraphenoxy borate can be used as template substrate which can be easily made in large scale. Due to the ionic nature of the borate, no supporting electrolyte is required. This methodology can be applied to several related phenolic substrates. The second route is described by the direct conversion of 2,4-dimethylphenol on boron-doped diamond anodes. Surprisingly, the electrochemical transformation does not destruct or mineralize the substrate. Fluorinated additives allow the conversion of a broad scope of substrates.