Ring-opening Research Articles

Degradation of oxytetracycline in soil by a Pseudomonas strain

Oxytetracycline (OTC) is used extensively in animal husbandry and enters the soil in different forms, causing severe environmental pollution. Previous studies have shown that the genus Pseudomonas can potentially degrade antibiotics in the soil environment. Environmental conditions, such as the initial concentration of antibiotics, incubation temperature and others, have significant impacts on the activity of antibiotic-degrading bacteria. However, few reports have clarified the environmental impacts on the effectiveness of Pseudomonas spp. In the present study, we investigated the effects of different initial concentrations of OTC and incubation temperatures, as well as soil sterilization, on OTC degradation by Pseudomonas <pg=>strain T4. We also focused on the microbial degradation pathways of OTC, and variations in both antibiotic resistance genes (ARGs) and microbial communities with T4 functioning under optimal conditions. The results showed that the most effective degradation occurred under an initial OTC concentration of 2.5 mg kg-1 at 30°C in unsterilized soil spiked with T4. These conditions yielded an OTC degradation rate of 69.53% within 63 days. The putative degradation pathways of OTC in the presence of T4 included dehydration, demethylation, deamination, hydroxylation, oxidation and ring opening. Bacteroidetes, Proteobacteria and Acidobacteria played key roles in the biodegradation of OTC with T4 in the soil. The results also showed that tet(G) was the most frequently detected among the 13 common tetracycline ARGs that were investigated. The bacterial community shift observed in this study may provide new insights into the microbial degradation of OTC in soil.

Can OPAH Ions be a Source of CO and HCO in the Interstellar Medium? Lessons Learned From the Unimolecular Dissociation of Dibenzofuran and Dibenz[b,f]oxepin Radical Cations

Unlike polycyclic aromatic hydrocarbons (PAHs), which are recognized to be key players in interstellar and astrochemistry, less is known about the astrochemical relevance of oxygen-containing PAHs (OPAHs). Small O-containing molecules such as CO and HCO are ubiquitous in the interstellar medium and understanding how OPAHs may be a source for these critical small molecules is important. To this end, we have studied the unimolecular reactions of two ionized OPAHs, dibenzofuran (1+•) and dibenz[b,f]oxepin (2+•) with tandem mass spectrometry (collision-energy resolved dissociation) and imaging photoelectron photoion coincidence spectroscopy (iPEPICO). Collision-induced dissociation (CID) results show the competition between the loss of carbon monoxide (CO) and loss of 29Da (either the formyl radical (HCO) or sequential H loss), with the latter being the dominant reaction. Rice–Ramsperger–Kassel–Marcus (RRKM) modeling of the iPEPICO data, on the other hand, is consistent with the loss of CO from the parent ion at the dissociative ionization onset, and, in the case of 2+•, sequential H-atom loss from this product. There is significant difference between the two structurally similar systems. In 1+•, dissociation requires around 4 eV of ion internal energy, while only 2.5 eV internal energy is required for 2+• to fragment. Calculations at the CAM-B3LYP/6-311++G(d,p) level of theory were used to examine the reaction pathways. For CO loss in 1+•, the reaction is initiated by a ring expansion followed by contraction of the central ring forming an ion–molecule complex between protonated cyclopenta[3,4]cyclobuta[1,2]benzene and CO. HCO loss is preceded by H migration to a bridging carbon vicinal to the oxygen atom and subsequent ring re-organization to form a low energy cyclopenta[c][1]benzopyran cation. This channel is higher enough in energy to preclude its participation near threshold, but not at higher internal energies reached in the CID experiment, which could therefore involve both sequential H loss and HCO loss. In 2+•, the reaction starts with an opening of the central O-containing ring, lowering the energy demand relative to 1+•.

Batch vs Continuous‐Flow Method to Synthesize N‐(3‐acylamidopropyl)lactams through N‐C Bond Cleavage in Amides with Amidines

The selective N‐C bond cleavage of amides to create value‐added products through a transition metal‐free approach has become a significant challenge. Here, we present a method to convert amides into N‐(3‐acylamidopropyl)lactams through sequential amide chemoselective N‐C bond cleavage and amidine ring opening under mild conditions, applicable in batch and continuous flow processes. These methods utilize bench‐stable reagents and are operationally straightforward and mild, enabling synthesis on a gram scale with excellent functional group tolerance. Additionally, the synthetic feasibility of these reactions under flow conditions has proven to be highly efficient, providing N‐(3‐acylamidopropyl)lactam derivatives with improved yields and shorter reaction time.

Atomically dispersed Fe boosting elimination performance of g-C3N4 towards refractory sulfonic azo compounds via catalyst-contaminant interaction

Herein, an oxygen-doped porous g-C3N4 photocatalyst modified with atomically dispersed Fe (Fe1/OPCN) is successfully prepared and exhibits significant superiority in removing refractory sulfonic azo contaminants from water via catalyst-contaminant interaction. The elimination performance of Fe1/OPCN towards acid red 9, acid red 13 and amaranth containing similar azonaphthalene structure and increasing sulfonic acid groups increases gradually. The amaranth degradation rate of Fe1/OPCN is 17.7 and 6.1 times as that of homogeneous Fenton and OPCN, respectively. In addition, Fe1/OPCN also has more outstanding removal activities towards other contaminants with sulfonic acid and azo groups alone. The considerable enhancement for removing sulfonic azo contaminants of Fe1/OPCN is mainly ascribed to the following aspects: (1) The modified Fe could enhance the adsorption towards sulfonic azo compounds to accelerate the mass transfer, act as e- acceptor to promote interfacial charge separation, and trigger the self-Fenton reaction to convert in-situ generated H2O2 into •OH. (2) Fe(Ⅲ) could coordinate with —N=N— to form d-π conjugation, which could attract e- transfer to attack —N=N— bond. Meanwhile, the inhibited charge recombination could release more free h+ to oxidize sulfonic acid groups into SO4-•. (3) Under the cooperation of abundant multiple active species (•O2-, h+, e-, •OH, SO4-•) formed during the degradation reaction, sulfonic azo compounds could be completely mineralized into harmless small molecules (CO2, H2O, etc.) by means of —N=N— cleavage, hydroxyl substitution, and aromatic ring opening. This work offers a novel approach for effectively eliminating refractory sulfonic azo compounds from wastewater.

Facile Synthesis of Phthalazinone/Isoindolinone Substituted Fluorescence Active Indolo[1,2‐a]quinoxaline Derivatives via ANRORC and Fluorescence Turn Off Sensing of Fe2+

AbstractSynthesis of a series of indolo[1,2‐a]quinoxaline derivatives substituted with phthalazinones/isoindolinones/carbonyl benzoylesters at C‐4 position have been accomplished under open air rt/heating conditions following ANRORC (Addition of Nucleophile, Ring Opening and Ring Closure) mechanism. Initially condensation of 2‐(1‐indolyl)‐aniline and ninhydrin generates a spirocyclic intermediate 5′H‐spiro[indene‐2,6′‐indolo[1,2‐a]quinoxaline]‐1,3‐dione, which upon reaction with various nucleophiles like hydrazine/phenylhydrazine, amines and alcohols affords C‐4 substituted indolo[1,2‐a]quinoxalines in high yield (up to ~88 %) via ANRORC. The photophysical investigation shows that the quinoxaline derivatives possess significant fluorescence property with high quantum yield (QY~11.0–17.0). The N‐phenylphthalazinone substituted indolo[1,2‐a]quinoxaline, a molecule structurally similar to 2,2′‐bipyridine system, can efficiently and selectively detect Fe2+ through fluorescence turn off sensing.

Assessment on the rings cleavage mechanism of polycyclic aromatic hydrocarbons in supercritical water: A ReaxFF molecular dynamics study

The ring opening reaction of polycyclic aromatic hydrocarbons (PAHs) is one of the rate-determining steps of coal gasification within supercritical water, while the involvement of water remains debated between addition and hydrogen abstraction theories. In this study, reactive molecular dynamics (MD) simulations were performed to explore the ring opening reaction of naphthalene, the simplest PAH, at temperatures of 2500–2700 K. Species and elementary reactions were quantitatively extracted from bond order trajectories using an in-house program. Reaction path analysis shows that ring opening paths of naphthalene mainly include thermolysis, H˙ atom abstraction, and O˙H radical addition. Flux analysis indicates O˙H radical largely from the H˙ + ▪ = O˙H + ▪ reaction, while the water dissociation ▪ = O˙H + H˙ reaction is near equilibrium, seldom contributing to the O˙H source. This atomistic kinetics analysis is intended to help the modeling of supercritical water gasification of coal.

Synthesis and Optimization of Foam Copper-Based CoMnOx@Co3O4/CF Catalyst: Achieving Efficient Catalytic Oxidation of Paraxylene.

This study successfully developed a foam copper (CF)-based CoMnOx@Co3O4/CF composite catalyst, achieving efficient thermal catalytic oxidation of paraxylene through multifactor optimization of synthesis conditions. At a Co:Mn molar ratio of 2:1 and a calcination temperature of 450 °C, the catalyst exhibited outstanding catalytic performance, with a T90 temperature as low as 246 °C, significantly lower than that of catalysts synthesized under other conditions. Additionally, BET, XPS, Raman, EPR, and H2-TPR test results indicate that the catalyst possesses a high specific surface area, abundant oxygen vacancies, a distribution of multivalent Co and Mn species, and a lower hydrogen reduction temperature, all of which contribute to the high catalytic activity of CoMnOx@Co3O4/CF. Furthermore, in situ DRIFTS confirmed that the oxidation of paraxylene on CoMnOx@Co3O4/CF follows the Mars-Van Krevelen (MvK) mechanism. The proposed reaction pathway begins with the oxidation of the methyl group on paraxylene, followed by the opening of the benzene ring and further oxidation to CO2 and H2O. The innovative structural design and excellent catalytic performance of this catalyst provide new insights and solutions for the industrial treatment of VOCs.

Homologation of Alkenyl Carbonyls via a Cyclopropanation/Light-Mediated Selective C-C Cleavage Strategy.

We report herein our studies on the direct photoactivation of carbonyl cyclopropanes to give biradical intermediates, leading to selective cleavage of the more substituted carbon-carbon bond. Depending on the substrate structure, extended alkenes were isolated or directly reacted in a photo-Nazarov process to give bicyclic products. Based on these results, a unified reductive ring-opening reaction was developed by using diphenyl disulfide as a HAT reagent. By performing a sequential cyclopropanation/selective ring opening reaction, we achieved a CH2 insertion into the α,β bond of both acyclic and cyclic unsaturated carbonyl compounds. Our protocol provides a further tool for the modification of the carbon framework of organic compounds, complementing the recent progress in "skeletal editing".

Homologation of Alkenyl Carbonyls via a Cyclopropanation/Light‐Mediated Selective C‐C Cleavage Strategy

We report herein our studies on the direct photoactivation of carbonyl cyclopropanes to give biradical intermediates, leading to selective cleavage of the more substituted carbon‐carbon bond. Depending on the substrate structure, extended alkenes were isolated or directly reacted in a photo‐Nazarov process to give bicyclic products. Based on these results, a unified reductive ring‐opening reaction was developed by using diphenyl disulfide as a HAT reagent. By performing a sequential cyclopropanation/selective ring opening reaction, we achieved a CH2 insertion into the α,β bond of both acyclic and cyclic unsaturated carbonyl compounds. Our protocol provides a further tool for the modification of the carbon framework of organic compounds, complementing the recent progress in “skeletal editing”.

Selective monodeuteration enabled by bisphosphonium catalyzed ring opening processes

The selective incorporation of a deuterium atom into small molecules with high selectivity is highly valuable for medical and chemical research. Unfortunately, this remains challenging due to the complete deuteration caused by commonly used hydrogen isotope exchange strategies. We report the development of a photocatalytic selective monodeuteration protocol utilizing C–C bond as the unconventional functional handle. The synergistic combination of radical-mediated C–C bond scission and deuterium atom transfer processes enables the effective constructions of benzylic CDH moieties with high selectivity for monodeuteration. The combinational use of a bisphosphonium photocatalyst, thiol catalyst, and CH3OD deuteration agent provides operationally simple conditions for photocatalytic monodeuteration. Moreover, the photoinduced electron transfer process of the bisphosphonium photocatalyst is elucidated through a series of spectroscopy experiments, identifying a peculiar back electron transfer process that can be regulated by subsequent nucleophilic additions.

Oxidation of 4-hydroxybenzoic acid in strongly alkaline and high-salt solutions via ultrasonic-assisted ozone: Helping radioactive waste disposal and environmental safety

4-Hydroxybenzoic acid (4-HBA), as a gibbsite dissolution inhibitor and typical personal care products (PPCPs), seriously troubles radioactive waste disposal and environmental safety. This work studies the degradation mechanism of 4-HBA in ultrasonic-assisted ozonation in strongly alkaline and high-salt solutions, and comprehensively evaluates its environmental lifetime. Ultrasonic can significantly increase the effect of ozone by 1.52 times, making the degradation rate of 4-HBA reach 63.49 % within 60 min. The better electrochemical performance indicates that the redox reaction between US/O3 system and 4-HBA is more prominent. Experimental analysis and density functional theory (DFT) calculations show that the effects of OH, 1O2, O2−, and others on the degradation of 4-HBA are 56.6 %, 17.8 %, 22.1 %, and 3.5 % respectively, and HO3 is the most important precursor for OH evolution. Mechanistic exploration and DFT calculations show that degradation behavior of 4-HBA in strongly alkaline and high-salt solutions, i.e., decarboxylation reaction, ring opening, hydroxylation, aldol condensation, and hydrogenation, is significantly different from acidic or neutral solutions. Based on the environmental lifetime assessment of the intermediate product, US/O3 technology can help reduce the toxicity of 4-HBA. The US/O3 process is used to remove 4-HBA from strongly alkaline and high-salt solutions, which has huge potential economic benefits in the fields of nuclear waste chemistry and environment.

Revealing the Response of Structure and Decomposition Behaviors of 1, 1′‐Azobis‐1, 2, 3‐Triazole to Pressure: A Theoretical Study

ABSTRACT1, 1′‐azobis‐1, 2, 3‐triazole (C4H4N8, N8) is a novel nitrogen‐rich energetic material with excellent detonation performance, which has received widespread interest. Inspired by recent theories and experiments, the dependence of structural, vibrational, and electronic properties on high pressure up to 10 GPa was systematically investigated using periodic DFT calculations. It was found that the optimized structure belonged to the cis‐N8 structure through comparing the theoretical IR with experimental IR spectra. The third‐order Birch–Murnaghan equation of state for N8 was obtained up to 10 GPa, where the bulk modulus and its pressure derivative were 10.91 GPa and 7.689, respectively. More importantly, the pressure dependence of Laplacian bond order indicated that the five‐membered ring opening was the first step in the decomposition process, and that high pressure could inhibit the decomposition process of N8 due to the reinforcement of non‐covalent interactions. The present work could deepen the understanding of the energetic materials N8 under high pressure, and is of great significance to the blasting and detonation applications of N8.

Kinetic, Spectral and Mechanistic Regularities of New Reaction Systems With Chromogenic SN2‐Type Reaction for Detection of Epoxy Compounds

ABSTRACTNew reaction systems “oxirane – nucleophile X– – proton‐donor reagent AH – solvent” have been proposed for the detection of epoxides in which nucleophilic opening of the oxirane ring occurs accompanied by the formation of a colored product. The kinetic and mechanistic regularities of reactions in the proposed systems were investigated. Reaction orders with respect to the components of the systems have been determined: close to 1 – for oxirane and X−, close to 0 – for AH. It was shown that the proposed chromogenic reactions represent nucleophilic substitution of SN2‐type and allow the detection of epoxides containing both a terminal and internal epoxy group, which can be used to monitor processes in systems where epoxides are either the initial compounds or the synthesis products. Based on the conducted studies, it is possible to develop methods for the quantitative determination of epoxides using kinetic methods of analysis and UV–visible spectroscopy.

Simultaneous monitoring of epoxy value, hydroxyl value, and polymeric hydroxyl value during the ring opening of epoxidized soybean oils based on low‐field nuclear magnetic resonance coupled with chemometrics

AbstractLow‐field nuclear magnetic resonance technique combined with chemometrics was employed to establish the quantitative models for rapidly monitoring the changes of indicators (hydroxyl value (OHV), epoxy value (EV), polymeric hydroxyl value (POHV, reflecting the degree of polyetherification)) during the ring opening of epoxidized soybean oils. Comprehensively considering the variations of peak retention times and peak areas of LF‐NMR spectra, OHVs of vegetable oils‐based polyols were divided into low OHV (LOHV, 1.7–91.9 mg KOH/g) group and high OHV (HOHV, 94.1–229.4 mg KOH/g) group. In both LOHV and HOHV groups, OHV presented good linearity with T2w, S23, and STotal of relaxation property with correlation coefficient of &gt;0.90. EV and POHV also presented good linearity with relaxation property in both LOHV and HOHV groups. In LOHV group, data segment 1–1000 ms was taken with Deresolve, no preprocessing, and Deresolve as preprocessing methods for OHV, EV, and POHV, respectively, and partial least square (PLS) as the modeling method for all the three indicators, where RMSEPs of OHV, EV, and POHV models were 4.282, 0.114, and 4.061, respectively. In HOHV group, data segment 1–1000 ms was taken with no preprocessing as the preprocessing method and PLS as the modeling method for all the three indicators, where RMSEPs of OHV, EV, and POHV models were 3.117, 0.088, and 4.964, respectively. The established method will benefit polyol industry to online adjust the production parameters according to the monitoring results and achieve high‐quality of vegetable oils‐based polyols.

Ring-Opening α,β-Difunctionalization of Cyclopropanols with Azides Enables 4-Keto-Functionalized 1,2,3-Triazole Synthesis.

Selective C-C bond cleavage and transformation of organic small molecules to create products of increased value are one of the central goals in organic chemistry. In this study, we have developed a novel TEMPO-mediated ring-opening α,β-difunctionalization of cyclopropyl alcohols with organic azides to prepare structurally important 4-keto-1,2,3-triazoles under metal- and additive-free conditions. This protocol not only provides a straightforward and efficient method for the synthesis of 4-keto-functionalized 1,2,3-triazoles in one pot but also accomplishes the goal of constructing α,β-double C-N bonds via the ring opening of cyclopropyl alcohols for the first time. Additionally, the application of the skeletons of drugs and natural products and the synthesis of Kv1.5 channel blocker 4u further demonstrate the synthetic potential and practicability of this strategy.

Synthesis and Structure of Novel Hybrid Compounds Containing Phthalazin-1(2H)-imine and 4,5-Dihydro-1H-imidazole Cores and Their Sulfonyl Derivatives with Potential Biological Activities

A novel hybrid compound—2-(4,5-dihydro-1H-imidazol-2-yl)phthalazin-1(2H)-imine (5) was synthesized and converted into di-substituted sulfonamide derivatives 6a–o and phthalazine ring opening products—hydrazonomethylbenzonitriles 7a–m. The newly prepared compounds were characterized using elemental analyses, IR and NMR spectroscopy, as well as mass spectrometry. Single crystal X-ray diffraction data were collected for the representative compounds 5, 6c, 6e, 7g, and 7k. The antiproliferative activity of compound 5, sulfonyl derivatives 6a–o and benzonitriles 7a–m was evaluated on approximately sixty cell lines within nine tumor-type subpanels, including leukemia, lung, colon, CNS, melanoma, ovarian, renal, prostate, and breast. None of the tested compounds showed any activity against the cancer cell lines used. The antioxidant properties of all compounds were assessed using the DPPH, ABTS, and FRAP radical scavenging methods, as well as the β-carotene bleaching test. Antiradical tests revealed that among the investigated compounds, a moderate ABTS antiradical effect was observed for sulfonamide 6j (IC50 = 52.77 µg/mL). Benzonitrile 7i bearing two chlorine atoms on a phenyl ring system showed activity in a β-carotene bleaching test (IC50 = 86.21 µg/mL). Finally, the interaction AGE/RAGE in the presence of the selected phthalazinimines 6a, 6b, 6g, 6m, and hydrazonomethylbenzonitriles 7a, 7c–g, and 7i–k was determined by ELISA assay. A moderate inhibitory potency toward RAGE was found for hydrazonomethylbenzonitriles—7d with an electron-donating methoxy group (R = 3-CH3O-C6H4) and 7f, 7k with an electron-withdrawing substituent (7f, R = 2-Cl-C6H4; 7k, R = 4-NO2-C6H4).

Synthesis and Solvent Free DLP 3D Printing of Degradable Poly(Allyl Glycidyl Ether Succinate)

AbstractDigital light processing (DLP) printing forms solid constructs from fluidic resins by photochemically crosslinking polymeric resins with reactive functional groups. DLP is used widely due to its efficient, high‐resolution printing, but its use and translational potential has been limited in some applications as state‐of‐the‐art resins experience unpredictable and anisotropic part shrinkage due to the use of solvent needed to reduce resin viscosity and layer dependent crosslinking. Herein, poly(allyl glycidyl ether succinate) (PAGES), a low viscosity, degradable polyester, was synthesized by ring opening copolymerization and used in combination with degradable thiol crosslinkers to afford a solvent free resin that can be utilized in DLP printing. Varying resin formulations of PAGES polymer are shown to decrease part shrinkage from 14 % to 0.3 %. Photochemically printed parts fabricated from PAGES possess tensile moduli between 0.43 and 6.18 MPa and degradation profiles are shown to vary between 12 and 40 days under accelerated conditions based on degree of polymerization and crosslink ratio.

Novel insights into revealing the intrinsic degradation mechanism of ciprofloxacin by Chlorella sorokiniana: Removal efficiency, pathways and metabolism

Microalgae-mediated biodegradation of antibiotics has attracted increasing interest. However, the exact degradation mechanism behind it remains elusive, which is crucial for improving its efficiency and large-scale implementation. Therefore, this study aims to thoroughly investigate how Chlorella sorokiniana (C.sorokiniana) degrades ciprofloxacin (CIP) from the molecular level to elucidate its complicated degradation mechanism. Results show that C.sorokiniana exhibited an impressive removal rate of 38.05–74.29 % for CIP, the synergistic effect of biosorption and biodegradation was the main removal mechanism of CIP. The content of EPS increased by 11.84–103.31 %, acting as a carrier to increase the bioavailability of CIP. Enzyme activity analysis identified POD, CYP450, and GST as the major catalytic enzymes responsible for the biotransformation process of CIP with increases of 6–41.2 %, 18.78–102.1 % and 3.53–58.15 %, respectively. Molecular docking further revealed that the binding affinity of 146.24 μM, 27.71 μM and 16.33 μM was observed for POD,CYP450, and GST, respectively, indicating the high metabolic efficiency of CIP by CYP450. Finally, DFT calculations elucidated the enzyme-mediated biodegradation pathway of CIP, including hydroxylation, decarboxylation, and ring opening. These findings are expected to further fill the knowledge gap on the catalysis mechanism of CIP degradation by enzymes and improve the practical application of microalgae to antibiotic wastewater.

Simultaneous degradation of pharmaceuticals and personal care products in hospital wastewater using ozone under ultraviolet irradiation

The discharge of Pharmaceuticals and personal care products (PPCPs) from industries and hospitals are responsible for the contamination of water body with slow or non-degradable toxic compounds. The removal of these contaminants required advanced treatment process because of unable to treat by conventional wastewater treatment process. In this study, the degradation of PPCP compounds, including caffeine (CAF), atenolol (ATL), carbamazepine (CBZ), sulfamethoxazole (SMX), trimethoprim (TMP), and acetaminophen (ACT) was evaluated under exposure to 1.0 and 1.5 mg/L dissolved ozone (O3), both with and without ultraviolet (UV) irradiation (254 nm). Using liquid chromatography with tandem mass spectrometry, we determined that the removal efficiency for the targeted contaminants exceeded 95 % within just 20 min of exposure to both 1.0 and 1.5 mg/L O3. However, when treated with UV light alone, the removal efficiency was limited at 3 %–11 %. A combination treatment involving dissolved 1.5 mg/L O3 and UV light led to over 97 % removal within 7 min. This outcome was attributed to hydroxylation reactions, aromatic ring opening, oxidation, and mineralization facilitated by the HO and peroxide generated through the photolysis of O3. The degradation rate of PPCP compounds followed pseudo-first-order kinetics and showed a decrease in the presence of humic acid and hospital wastewater further decreased it. Moreover, O3/UV treatment generated lower-weight degradation products. The toxicity analysis revealed that these transformation products exhibited environmental benignity and minimal health risks which O3/UV treatment potentially minimizes the presence of harmful byproducts. These findings provide a foundation for developing combined hybrid systems for PPCP containing wastewater, containing membrane filtration with ozonation system.

Copper-Catalyzed 1,3-Aminocyclization of Cyclopropanes as a Rapid Entry to γ-Amino Heterocycles.

We herein report a copper-catalyzed 1,3-aminocyclization of cyclopropanes as a direct and versatile entry into important heterocycles. This reaction was initiated by a copper-catalyzed, NFSI-promoted ring opening of cyclopropanes, followed by nucleophilic cyclization. A variety of nucleophiles successfully participate in this transformation, including alcohols, carboxylic acids, sulfonamides, and amides, for the construction of diverse cyclic ethers, pyrrolidines, lactones, and iminolactones.