Acyclic Ethers Research Articles

Kinetic insights into double-branched acyclic ether: Methyl tert-butyl ether and 2,2-dimethoxypropane

This study presents the first kinetic mechanism for methyl tert-butyl ether (MTBE) containing low-temperature chemistry, as well as the first mechanism for 2,2-dimethoxypropane (DMP). The mechanisms have been validated against ignition delay time experiments conducted in a high-pressure shock tube and rapid compression machine. The rapid compression machine conditions were set to 20 and 40 bar for MTBE, and 10 and 20 bar for DMP in a temperature range of 584 to 946 K. Shock tube experiments have been performed for DMP at 20 and 40 bar for stoichiometric and fuel-lean conditions in air at temperatures ranging from 913 to 1173 K. A pronounced negative temperature coefficient regime with two-stage ignition has been observed for both fuels. The developed mechanism consists of reaction rate constants that were primarily modeled in analogy to iso-octane and dimethoxymethane, and calculated thermodata on the G4//B3LYP-D3BJ/def2-TZVP level of theory. Simulations have been performed to analyze the fuel oxidation at different temperatures. Over the full temperature range, H-atom abstraction occurs mainly on the α-side for DMP and on the β-side for MTBE. At low temperatures, both fuels isomerize to the peroxy radical. The dominant MTBE radicals then tend to produce cyclic ether, while the DMP radicals react with O2, enabling significant chain branching and explaining the higher reactivity of DMP. With rising temperature, β-scission of the fuel radicals and unimolecular elimination reactions start to dominate the oxidation process.Novelty and Significance StatementThe novelty of this research is the first observation of a two-stage ignition of methyl-tert butyl ether (MTBE) in an RCM and a discussion of its fundamental ignition chemistry, which is based on a developed detailed kinetic mechanism. In addition, 2,2-dimethoxypropane (DMP) has been investigated experimentally and theoretically to explain the difference in reactivity to MTBE despite their strong molecular similarity. The experiments include RCM and shock tube experiments. The kinetic model is based on rate constant analogies and newly calculated thermo data on the G4//B3LYP-D3BJ/def2-TZVP level of theory. This work is significant, as MTBE is still a widely used octane booster and the developed model could help to improve engine simulations. Furthermore, the findings of DMP provide insights into future fuel design.

Experimental-computational study on the competition between 1,2-dimethoxyethane and tetrahydrofuran in a MACC-based electrolyte

The 1:1 MgCl2:AlCl3 (MACC)-based electrolyte was spectroscopically investigated for the first time in the presence of an equimolal 1,2-dimethoxyethane (DME):tetrahydrofuran (THF) mixture. Composition-dependent Raman spectra suggested that the new bands at 896 and 883 cm−1 correspond to the mixed νCO and νCC vibrations of both ethers coordinated to Mg(II) ions. A signal at 219 cm−1, which is assigned to the νMgCl vibration, was only observed for the highest acid-base pair content, in contrast to the behavior exhibited in the acyclic ether alone. Density functional theory (DFT) calculations and ab initio molecular dynamics (AIMD) simulations revealed that the [MgCl(DME)(THF)3]+ and [MgCl(DME)2THF]+ monomers may be associated to the experimental bands observed at the solvent region, thus being predicted at 867 and 858 cm−1, respectively. The [Mg2(μ-Cl)2(DME)4]2+ dimer has a theoretical band at 216 cm−1, which is related to the experimentally observed signal at the low wavenumber region. The preferential solvation effect is discussed in detail for the studied solvates.

SN 2 versus E2 Competition of Cyclic Ethers.

We have quantum chemically studied the influence of ring strain on the competition between the two mechanistically different SN 2 and E2 pathways using a series of archetypal ethers as substrate in combination with a diverse set of Lewis bases (F- , Cl- , Br- , HO- , H3 CO- , HS- , H3 CS- ), using relativistic density functional theory at ZORA-OLYP/QZ4P. The ring strain in the substrate is systematically increased on going from a model acyclic ether to a 6- to 5- to 4- to 3-membered ether ring. We have found that the activation energy of the SN 2 pathway sharply decreases when the ring strain of the system is increased, thus on going from large to small cyclic ethers, the SN 2 reactivity increases. In contrast, the activation energy of the E2 pathway generally rises along this same series, that is, from large to small cyclic ethers. The opposing reactivity trends induce a mechanistic switch in the preferred reaction pathway for strong Lewis bases from E2, for large cyclic substrates, to SN 2, for small cyclic substrates. Weak Lewis bases are unable to overcome the higher intrinsic distortivity of the E2 pathway and, therefore, always favor the less distortive SN 2 reaction.

Visible-Light-Mediated (sp 3)Cα-H Functionalization of Ethers Enabled by Electron Donor-Acceptor Complex.

A synthetically beneficial visible-light-mediated protocol has been disclosed to achieve C-H amination of readily available feedstocks cyclic and acyclic ethers. A rarely identified N-bromosuccinamide-tetrahydrofuran electron donor-acceptor complex served as an initiator to functionalize both α-diazoketones and dialkyl azodicarboxylates. This developed methodology gives an alternative and milder way to construct the C-N bond and can be explored for the formation of C-C bond to perform arylation and allylation reactions.

Silver(I)-Catalyzed Reductive Cross-Coupling of Aldehydes to Structurally Diverse Cyclic and Acyclic Ethers.

A range of medium-sized cyclic ethers (5 to 11 membered) have been effectively synthesized through intramolecular reductive coupling of dialdehydes initiated by 50 ppm to 0.5% of AgNTf2 with hydrosilane at 25 °C. The catalytic system is also suitable for the coupling of two different monoaldehydes to provide unsymmetrical ethers. This protocol features broad functional group compatibility, high product diversity, high efficiency, and utility in the late-stage modification of complex biorelevant molecules.

Chemical insights into the multi-regime low-temperature oxidation of di-n-propyl ether: Jet-stirred reactor experiments and kinetic modeling

To further understand the combustion characteristics and the reaction pathways of acyclic ethers, the oxidation of di-n-propyl ether (DPE) was investigated in a jet-stirred reactor (JSR) combined with a photoionization molecular-beam mass spectrometer. The experiments were carried out at near-atmospheric pressure (700 Torr) and over a temperature range of 425–850 K. Based on the experimental data and previous studies on ether oxidation, a new kinetic model was constructed and used to interpret the oxidation chemistry of DPE. In DPE oxidation, a high reactivity at low temperatures and two negative temperature coefficient (NTC) zones were observed. These behaviors are explained in this work by taking advantage of the obtained species information and the modeling analyses: the two NTC zones are caused by the competition of chain branching and termination reactions of the fuel itself and specific oxidation intermediates, respectively. Furthermore, the general requirements to have double-NTC behavior are discussed. A variety of crucial fuel-specific C6 species, such as ketohydroperoxides and diones, were detected in the species pool of DPE oxidation. Their formation pathways are illuminated based on rate-of-production (ROP) analyses. Propanal was identified as the most abundant small molecule intermediate, and its related reactions have an important impact on the oxidation process of DPE. Both acetic acid and propionic acid were detected in high concentrations. A new formation pathway of propionic acid is proposed and incorporated into the kinetic model to achieve a more accurate prediction for propionic acid mole fractions.

Machine learning-quantitative structure property relationship (ML-QSPR) method for fuel physicochemical properties prediction of multiple fuel types

A machine learning-quantitative structure property relationship (ML-QSPR) method is proposed to predict 15 fuel physicochemical properties of 23 fuel types. QSPR-UOB 3.0 functional group classification system is developed to extract and digitalize the molecular structure feature. ML algorithms are used to map the molecular structure feature and fuel properties as well as model parameter tuning. UOB Fuel Property Database (1797 pure compounds and 465 mixtures) is established to provide massive properties data for model training. Cross-validation is chosen to examine predictive precision, avoid overfitting and estimate inter/extrapolation capacity. ML-QSPR method has 4 distinct advantages compared to published statistical methods: (1) It applies to 15 properties of CN, RON, MON, Tm, Tb, ΔHvap, surface tension γ, LHV, liquid density ρ, YSI, IT, FP, VP, LFL, UFL. (2) It applies to 23 fuel types of alkanes, cycloalkanes, alkenes, cyclic alkenes, alkadienes, alkynes, alcohols, cycloalcohols, aldehydes, ketones, cyclic ketone, saturated esters, unsaturated esters, acyclic ethers, furans, other cyclic ethers, aromatics, carbonate ester, carboxylic anhydride, peroxide, hydroperoxide, polyfunctionals, carboxylic acids. (3) High predictive accuracy is achieved and the average R2 of 15 fuel properties reaches 0.9816. (4) The regression models display reasonable interpolation and extrapolation capacity to test new molecules. The success is attributed to 2 key factors: (1) QSPR-UOB 3.0 system accounts for the contribution of structural features, functional group interaction and fuel reactivity. (2) ML algorithms accurately capture the dependence of fuel properties on chemical structures.

Gas-Phase Rate Coefficient of OH + 1,2-Epoxybutane Determined between 220 and 950 K

Epoxides have many primary and secondary atmospheric sources. As with other oxygenates, they exhibit a complex temperature-dependent reaction with OH, whose full description is necessary in order to understand their interactions in atmospheric and combustion environments. We measured the kinetics of the title reaction using two complementary absolute methods: pulsed-laser photolysis–laser-induced fluorescence (PLP–LIF) and a discharge-flow mass spectrometric system (DF-MS), both monitoring temporal decays in OH. In addition, two relative methods employing the DF-MS as a function of temperature as well as several simulation chamber experiments at room temperature were performed. A very weak negative temperature dependence was observed at T ≤ 285 K, and only through the combination of precise data and a large temperature range were we able to discern the transition toward positive temperature dependence found at T ≥ 295 K. The non-Arrhenius temperature dependence of OH + 1,2-epoxybutane implies the agency of prereactive complexes in this reaction mechanism, albeit with a smaller effect than that with its acyclic ether analogues. This will have implications for understanding the chemical fate of epoxides within oxidizing environments.

Synthetic and Mechanistic Implications of Chlorine Photoelimination in Nickel/Photoredox C(sp3)-H Cross-Coupling.

In recent years, the development of light-driven reactions has contributed numerous advances in synthetic organic chemistry. A particularly active research area combines photoredox catalysis with nickel catalysis to accomplish otherwise inaccessible cross-coupling reactions. In these reactions, the photoredox catalyst absorbs light to generate an electronically excited charge-transfer state that can engage in electron or energy transfer with a substrate and the nickel catalyst. Our group questioned whether photoinduced activation of the nickel catalyst itself could also contribute new approaches to cross-coupling. Over the past 5 years, we have sought to advance this hypothesis for the development of a suite of mild and site-selective C(sp3)-H cross-coupling reactions with chloride-containing coupling partners via photoelimination of a Ni-Cl bond.On the basis of a report from the Nocera laboratory, we reasoned that photolysis of a Ni(III) aryl chloride species, generated by single-electron oxidation of a typical Ni(II) intermediate in cross-coupling, might allow for the catalytic generation of chlorine atoms. Combining this with the ability of Ni(II) to accept alkyl radicals, we hypothesized that photocatalytically generated chlorine atoms could mediate hydrogen atom transfer (HAT) with C(sp3)-H bonds to generate a substrate-derived alkyl radical that is captured by the Ni center in cross-coupling. A photoredox catalyst was envisioned to promote the necessary single-electron oxidation and reduction of the Ni catalyst to facilitate an overall redox-neutral process. Overall, this strategy would offer a visible-light-driven mechanism for chlorine radical formation enabled by the sequential capture of two photons.As an initial demonstration, we developed a Ni/photoredox-catalyzed α-oxy C(sp3)-H arylation of cyclic and acyclic ethers. This method was extended to a mild formylation of abundant and complex aryl chlorides through selective 2-functionalization of 1,3-dioxolane. Seeking to develop a suite of reactions that introduce carbon at all different oxidation states, we explored C(sp3)-H cross-coupling with trimethyl orthoformate, a common laboratory solvent. We found that trimethyl orthoformate serves as a source of methyl radical for a methylation reaction via β-scission from a tertiary radical generated upon chlorine-mediated HAT. Since chlorine radical is capable of abstracting unactivated C(sp3)-H bonds, our efforts have also been directed at cross-coupling with a range of feedstock chemicals, such as alkanes and toluenes, along with late-stage intermediates, using chloroformates as coupling partners. Overall, this platform enables access to valuable synthetic transformations with (hetero)aryl chlorides, which despite being the most ubiquitous and inexpensive aryl halide coupling partners, are rarely reactive in Ni/photoredox catalysis.Little is known about the photophysics and photochemistry of organometallic Ni complexes relevant to cross-coupling. We have conducted mechanistic investigations, including computational, spectroscopic, emission quenching, and stoichiometric oxidation studies, of Ni(II) aryl halide complexes common to Ni/photoredox reactions. These studies indicate that chlorine radical generation from excited Ni(III) is operative in the described C(sp3)-H functionalization methods. More generally, the studies illustrate that the photochemistry of cross-coupling catalysts cannot be ignored in metallaphotoredox reactions. We anticipate that further mechanistic understanding should facilitate new catalyst design and lead to the development of new synthetic methods.

Oxidative Radical-Mediated Addition of Ethers to Quinone Imine Ketals: An Access to Hemiaminals.

The highly regioselective synthesis of substituted hemiaminal via addition of ethers to quinone imine ketals (QIKs) has been developed under metal-free conditions. In the presence of tetrabutylammonium chloride and potassium persulfate (K2S2O8), QIKs couple efficiently with cyclic and acyclic ethers to give hemiaminals. This strategy offers an easy access to substituted hemiaminal ethers with high functional group tolerance in good to excellent yields.

Mechanisms of Formation and Rearrangement of Benziodoxole-Based CF3 and SCF3 Transfer Reagents.

Togni’s benziodoxole-based reagents are widely used in trifluoromethylation reactions. It has been established that the kinetically stable hypervalent iodine form (I–CF3) of the reagents is thermodynamically less stable than its acyclic ether isomer (O–CF3). On the other hand, the trifluoromethylthio analogue exists in the thermodynamically stable thioperoxide form (O–SCF3), and the hypervalent form (I–SCF3) has been elusive. Despite the importance of these reagents, very little is known about the reaction mechanisms of their syntheses, which has hampered the development of new reagents of the same family. Herein, we use density functional theory calculations to understand the reasons for the divergent behaviors between the CF3 and SCF3 reagents. We demonstrate that they follow different mechanisms of formation and that the metals involved in the syntheses (potassium in the case of the trifluoromethyl reagent and silver in the trifluoromethylthio analogue) play key roles in the mechanisms and greatly influence the possibility of their rearrangements from the hypervalent (I–CF3, I–SCF3) to the corresponding ether-type form (O–CF3, O–SCF3).

α-Pyridinyl Alcohols, α,α'-Pyridine Diols, α-Bipyridinyl Alcohols, and α,α'-Bipyridine Diols as Structure Motifs Towards Important Organic Molecules and Transition Metal Complexes.

The preparation and use of pyridinyl alcohols as ligands showed incredible increment in the past three decades. Important property of pyridinyl alcoholato ligands is their strong basicity, which is mainly due to the lack of resonance stabilization of the corresponding anion. This strongly basic anionic nature gives them high ability to make bridges between metal centers rather than to bind to only one metal center in a terminal fashion. They are needed as ligands due to their ability to interact with transition metals both covalently (with oxygen) and hemilabile coordination (through nitrogen). The review focuses on the wide application of α-pyridinyl alcohols, α,α'-pyridine diols, α- bipyridinyl alcohols, and α,α'-bipyridine diols as structure motifs in the preparation of important organic molecules which is due to their strongly basic anionic nature. It is clear from the review that in addition to their synthetic utility in the homogeneous and asymmetric catalytic reactions, the preparation of the crown ethers, cyclic and acyclic ethers, coordinated borates (boronic esters), pyridinyl-phosphine ligands, pyridinyl-phosphite ligands, and pyridinyl-phosphinite ligands is the other broad area of application of pyridinyl alcohols. In addition to the aforementioned applications they are used for modeling mode of action of enzymes and some therapeutic agents. Their strongly basic anionic nature gives them high ability to make bridges between metal centers rather than to bind to only one metal center in a terminal fashion in the synthesis of transition metal cluster complexes. Not least numbers of single molecule magnets that can be used as storage of high density information were the result of transition metal complexes of pyridinyl alcoholato ligands.

Iron-Catalyzed Direct Cross-Coupling of Ethers and Thioether with Alcohols for the Synthesis of Mixed Acetals

An iron-catalyzed direct O-alkylation of alcohols via α-C(sp3)–H activation of ethers and a thioether has been established that tolerates cyclic and acyclic ethers and alcohols containing aromatic N-heterocyclic moieties, providing an efficient and green method for the synthesis of mixed acetals with good to excellent yields. The robustness of this protocol is demonstrated by the late-stage oxidation of a structurally complex natural product.

Decarbonylative ether dissection by iridium pincer complexes.

A unique chain-rupturing transformation that converts an ether functionality into two hydrocarbyl units and carbon monoxide is reported, mediated by iridium(i) complexes supported by aminophenylphosphinite (NCOP) pincer ligands. The decarbonylation, which involves the cleavage of one C–C bond, one C–O bond, and two C–H bonds, along with formation of two new C–H bonds, was serendipitously discovered upon dehydrochlorination of an iridium(iii) complex containing an aza-18-crown-6 ether macrocycle. Intramolecular cleavage of macrocyclic and acyclic ethers was also found in analogous complexes featuring aza-15-crown-5 ether or bis(2-methoxyethyl)amino groups. Intermolecular decarbonylation of cyclic and linear ethers was observed when diethylaminophenylphosphinite iridium(i) dinitrogen or norbornene complexes were employed. Mechanistic studies reveal the nature of key intermediates along a pathway involving initial iridium(i)-mediated double C–H bond activation.

Visible Light Mediated C(sp3)‐H Alkenylation of Cyclic Ethers Enabled by Aryl Ketone

AbstractC−H alkenylation of cyclic ethers (THF, 1,4‐dioxane) using the readily available nitroalkenes as the alkenylating reagents has been developed. It allows the rapid access to the α‐alkenyl ethers with high E‐selectivity. The previous inaccessible α‐dienyl ethers are successfully obtained. Acyclic ether can also participate in this alkenylation process. The mechanism study reveals that alkenylation proceeded through a proton coupled electron transfer (PCET) process with a de‐nitration.

New Methods for the Synthesis of Alkoxy Derivatives of the closo-Decaborate Anion [2-B10H9(OR)]2–, Where R = C2H5, iso-C3H7, С4H9

A two-stage scheme was proposed for the synthesis of alkoxy derivatives of the closo-decaborate anion [B10H9(OR)]2–, where R = C2H5, iso-C3H7, C4H9. At the first stage, the oxonium derivatives with the general formula [B10H9(OR2)]– were synthesized by the reaction between the [B10H11]–anion and acyclic ethers. At the second stage, the synthesized oxonium derivatives reacted with hydrazine hydrate to form the alkoxy derivatives with the general formula [B10H9(OR)]2–, where R = C2H5, iso-C3H7, C4H9. This approach appreciably increased the yield of target products and simplified their separation. The alkoxy derivatives were separated and characterized by IR and 1H, 11B, and 13C NMR spectroscopy.

Functionalization of 1,3-diphosphacyclobutadiene cobalt complexes via Si–P bond insertion

AbstractWe report the synthesis of functionalized 1,3-bis(diphosphacyclobutadiene) complexes via the insertion of carbon-oxygen bonds of ethers, esters, aldehydes and amides into the P–Si bond of silylated complexes. Reactions of [K(tol)2][Co(η4-P2C2R2)2] [[K(tol)2][1a]:R=tBu,[K(tol)2][1b]:R=tPent (=tert-pentyl)] with Me3SiCl afford the trimethylsilyl-substituted derivatives [Co(η4-P2C2R2SiMe3)(η4-P2C2R2)] (2a,b, R=tBu,tPent). The Me3Si group is connected to a phosphorus atom of one of the 1,3-diphosphacyclobutadiene ligands.2a,breadily react with organic substrates containing C–O single and C=O double bonds at ambient temperature. [Co(η4-P2C2R2(CH2)4OSiMe3)(η4-P2C2R2)] (3a,b) are formed by reaction of2a,bwith traces of THF. They can also be isolated by reacting the THF solvates [K(thf)2{Co(P2C2tBu2)2}] ([K(thf)2][1a]) and [K(thf)3{Co(P2C2tPent2)2}] ([K(thf)3][1b]) with Me3SiCl in toluene or THF. The adamantyl-substituted complex [Co(η4-P2C2Ad2(CH2)4OSiMe3)(η4-P2C2Ad2)] (3c) was prepared analogously from [K(thf)4{Co(P2C2Ad2)2}] and Me3SiCl.[K(thf)2][1a]reacts cleanly with Ph3SnCl affording [Co(η4-P2C2tBu2SnPh3)(η4-P2C2tBu2)] (4) in high yield. Reaction of2awith styrene oxide affords [Co(η4-P2C2tBu2PhC2H3OSiMe3)(η4-P2C2tBu2)] (5) as a single regioisomer. By contrast, multinuclear NMR spectroscopic studies indicate mixtures of two isomeric insertion products6/6′ and7/7′, respectively, which result from the insertion of 1,2-epoxy-2-methylpropane and 1,2-epoxyoctane. Moreover, these monitoring studies show that reactions of2awith acyclic ethers afford alkyl substituted complexes such as [Co(η4-P2C2tBu2Et)(η4-P2C2tBu2)] (8) and alkylsilyl ethers. Reaction of2awithγ-butyrolactone gives [Co(η4-P2C2tBu2(CH2)3C(O)OSiMe3)(η4-P2C2tBu2)] (9) via cleavage of the endocyclic C–O single bond of the lactone. Benzaldehyde and acetone cleanly react with2ato [Co(η4-P2C2tBu2CH(Ph)OSiMe3)(η4-P2C2tBu2)] (10) and [Co(η4-P2C2tBu2CMe2OSiMe3)(η4-P2C2tBu2)] (11), while the sterically more demanding ketones 3-pentanone and acetophenone selectively yield the known hydride complex [Co(η4-P2C2tBu2)2H] (A). Phenyl isocyanate reacts with2aat elevated temperature to form [Co(η3-P2C2tBu2CON(Ph)SiMe3)(η4-P2C2tBu2)] (12) with a functionalizedη3-coordinated ligand.[K(tol)2][1a],[K(tol)2][1b],2a,2b,3a–c,4,5, and9–12were isolated and characterized by multinuclear NMR spectroscopy, UV/Vis spectroscopy and elemental analysis.[K(tol)2][1b],2a,2b,3c,4,5, and9–12were additionally characterized by X-ray crystallography.

Tetraglymes as Prochiral Host Reagents for Ammonia Borane

The molecular structure of the complex of ammonia borane (AB) with acyclic ether tetraglyme Me(OCH2CH2)4OMe (1), 1·(AB)2 was determined by single‐crystal X‐ray structure analysis for the first time. The crystal structure features two AB molecules, bonded by dihydrogen bonds, per one tetraglyme unit. The intermolecular BH···HN distances of 1.94 Å are shorter than those in the solid ammonia borane (2.02–2.32 Å). A comparison of the hydrogen and dihydrogen bonds in 1·(AB)2 and in the complexes of AB with crown‐ethers (CE) was carried out. The complex formation with both the CE and the acyclic polyether 1 activates the B–H bond in AB via N–H···O hydrogen bonds and therefore increases the reducing activity of AB. Supposedly, the structure of 1·(AB)2 is related to the initial steps of the AB activation in a polyether solution. The effect of the substituents on the complexation of the substituted derivatives of 1 comes down to a structural adjustment minimizing steric repulsion. Computations reveal that the complexation of diastereomeric disubstituted glymes with AB leads to the formation of diastereomeric complexes that differ noticeably in stability. This is a prerequisite for inducing stereoselectivity, which makes such complexes attractive for potential synthetic applications.

Nickel-Catalyzed Carbonylative Synthesis of Functionalized Alkyl Iodides

SummaryFunctionalized alkyl iodides are important compounds in organic chemistry and biology. In this communication, we developed an interesting nickel-catalyzed carbonylative synthesis of functionalized alkyl iodides from aryl iodides and ethers. With Mo(CO)6 as the solid CO source, both cyclic and acyclic ethers were activated, which is also a challenging topic in organic synthesis. Functionalized alkyl iodides were prepared in moderate to excellent yields with outstanding functional group tolerance. Besides the high value of the obtained products, all the atoms from the starting materials were incorporated in the final products and the reaction had high atom efficiency as well.

Aerobic Allylation of Alcohols with Non-Activated Alkenes Enabled by Light-Driven Selenium-π-Acid Catalysis

A new organocatalytic protocol for the aerobic dehydrogenative allylation of alcohols using non-activated alkenes as the allylating reagent and ambient air as the terminal oxidant is established. Mechanistically, the procedure relies on the interplay of a diselane and a photo­redox catalyst by means of a light-induced electron transfer process. Under optimized conditions, a broad range of both cyclic and acyclic ethers is accessed with very high functional group tolerance and excellent regioselectivity.