Iodobenzene Diacetate Research Articles

An efficient and environment-friendly halogenation of imidazoheterocycles with Bu4NX (X = Cl, Br and I) using iodobenzene diacetate as oxidant

An efficient and environment-friendly method for the synthesis of 3-haloimidazopyridine derivatives has developed by the halogenation of imidazoheterocycles with Bu4NX (X = Cl, Br, and I) using iodobenzene diacetate as oxidant in ethanol. This protocol features with short reaction time for bromination and iodination, ambient temperature, facile operation, good functional group tolerance and good yeilds.

Cascade Reaction in Organic Hole Transport Layer Enables Efficient Perovskite Solar Cells.

The doped organic hole transport layer (HTL) is crucial for achieving high-efficiency perovskite solar cells (PSCs). However, the traditional doping strategy undergoes a time-consuming and environment-dependent oxidation process, which hinders the technology upgrades and commercialization of PSCs. Here, we reported a new strategy by introducing a cascade reaction in traditional doped Spiro-OMeTAD, which can simultaneously achieve rapid oxidation and overcome the erosion of perovskite by 4-tert-butylpyridine (tBP) in organic HTL. The ideal dopant iodobenzene diacetate was utilized as the initiator that can react with Spiro to generate Spiro⋅+ radicals quickly and efficiently without the participation of ambient air, with the byproduct of iodobenzene (DB). Then, the DB can coordinate with tBP through a halogen bond to form a tBP-DB complex, minimizing the sustained erosion from tBP to perovskite. Based on the above cascade reaction, the resulting Spiro-based PSCs have a champion PCE of 25.76 % (certificated of 25.38 %). This new oxidation process of HTL is less environment-dependent and produces PSCs with higher reproducibility. Moreover, the PTAA-based PSCs obtain a PCE of 23.76 %, demonstrating the excellent applicability of this doping strategy on organic HTL.

Cascade Reaction in Organic Hole Transport Layer Enables Efficient Perovskite Solar Cells

AbstractThe doped organic hole transport layer (HTL) is crucial for achieving high‐efficiency perovskite solar cells (PSCs). However, the traditional doping strategy undergoes a time‐consuming and environment‐dependent oxidation process, which hinders the technology upgrades and commercialization of PSCs. Here, we reported a new strategy by introducing a cascade reaction in traditional doped Spiro‐OMeTAD, which can simultaneously achieve rapid oxidation and overcome the erosion of perovskite by 4‐tert‐butylpyridine (tBP) in organic HTL. The ideal dopant iodobenzene diacetate was utilized as the initiator that can react with Spiro to generate Spiro⋅+ radicals quickly and efficiently without the participation of ambient air, with the byproduct of iodobenzene (DB). Then, the DB can coordinate with tBP through a halogen bond to form a tBP‐DB complex, minimizing the sustained erosion from tBP to perovskite. Based on the above cascade reaction, the resulting Spiro‐based PSCs have a champion PCE of 25.76 % (certificated of 25.38 %). This new oxidation process of HTL is less environment‐dependent and produces PSCs with higher reproducibility. Moreover, the PTAA‐based PSCs obtain a PCE of 23.76 %, demonstrating the excellent applicability of this doping strategy on organic HTL.

PIDA-promoted metal-free [3 + 2] heteroannulation of β-ketothioamides with 4-hydroxy coumarins: chemo-/regioselective access to furo[3,2-c]chromen-4-ones at room temperature.

Herein, we report a viable protocol to access furo[3,2-c]chromen-4-ones by engaging easily accessible 4-hydroxy coumarins as a three-atom CCO unit and thioamides as a C2 coupling partner, mediated by phenyliodine(III) diacetate (PIDA) at room temperature in a highly efficient and pot-/step-economical manner. This strategy not only avoids potential toxicity and tiresome workup conditions, but also features operational simplicity, a broad substrate scope, good functional group tolerance, high yields, easy scalability and exclusive selectivity. A mechanistic study has shown that this metal-free reaction is triggered by PIDA via activation of the β-carbon of 4-hydroxy coumarin, followed by a nucleophilic addition/intramolecular cyclization/dethiohydration cascade. High-resolution mass spectra (HRMS) study confirms the key intermediates involved during the course of the reaction, elucidating the reaction pathways, and demonstrates the excellent regio- and chemoselectivity of this approach.

Synthesis of fluoro-benzoxazepines via an I(iii)/BF3·Et2O-enabled 1,2-aryl migration/fluorination cascade

A metal-free method for constructing benzoxazepine backbone lies in an exclusive 1,2-aryl migration/ fluorination cascade process, which is enabled by a phenyliodine(iii) diacetate (PIDA)/BF3·Et2O reagents system.

Thiocyanate promoted difunctionalization and cyclization of unsaturated C-C bonds to construct 1-sulfur-2-nitrogen-functionalized alkenes and 2-thiocyanate indolines.

An unprecedented one-pot route to achieve highly regioselective 1-sulfur-functionalized 2-nitrogen-functionalized alkenes and 2-thiocyanate indolines from unsymmetrical ynamides (readily and generally available amides) using the commercially available inexpensive iodobenzene diacetate (PIDA) as the oxidant and potassium thiocyanate (KSCN) as the thiocyanate (SCN) source has been developed. The interconversion of thiocyanate (SCN) and isothiocyanate (NCS) groups simultaneously forms C-N and C-S bonds in this metal-free approach, while introducing important functional groups into homemade alkynes. A radical-chain mechanism, involving competing kinetically controlled chain transfer at the S atom and sterically-controlled chain transfer at the N atom of the thiocyanogen molecule in this mild approach, is proposed.

Naphtho[1,8-de][1,2]Oxazin-4-ol: Precursor to 1,2,8-Trisubstituted Naphthalenes and 1-Unsubstituted Naphtho[1,2-d]isoxazole 2-Oxide: A Novel Isomerization of the N-Oxide to Nitrile Oxide en Route to Isoxazol(in)es.

Naphtho[1,8-de][1,2]oxazin-4-ol and its acyl or benzyl derivatives ring open to various 2,8-dihydroxy-1-naphthonitriles, which, through (de)protection protocols and reduction, afford the target (E)-2-hydroxy-8-methoxy-1-naphthaldehyde. This was converted to its corresponding oxime, which was oxidatively o-cyclized with phenyliodine(III) diacetate (PIDA) to 9-methoxynaphtho[1,2-d]isoxazole 2-oxide. The latter, in deuterated DMSO at room temperature, was rearranged to its isomer 2-hydroxy-8-methoxy(naphthalen-1-yl)nitrile oxide. The isomerization was detected by time-course plot 1H NMR spectroscopy and further identified from its 13C NMR and HRMS spectra. The nitrile oxide was stable in (non)deuterated DMSO for at least 18 h. A 3,4-bis(2-hydroxy-8-methoxynaphthalen-1-yl)-1,2,5-oxadiazole 2-oxide, as a dimerization product or an isocyanate as a rearrangement isomer, was ruled out, the former by its HRMS spectrum and the latter by its 1,3-dipolar cycloaddition reactions to substituted isoxazoles.

Efficient Photolytic Halogenation and Oxidation of Unactivated Alkyl sp3 C—H Bonds with Iodine(III)

Comprehensive SummaryA metal‐free, green, and sustainable functionalization of unactivated alkyl sp3 C—H bonds is reported using iodine(III) as a feasible dehydrogenation agent under visible light or KBr, and alkyl chlorides, bromides, alcohols, and ketones could be constructed by addition of different coupling reagents. Cheap and safe iodobenzene diacetate was used to form a radical to activate the alkyl sp3 C—H bond in a highly efficient manner, which can construct different alkylation products by adding corresponding coupling reagents.

One-pot synthesis of N-acylated ureas using phenyliodine (III) diacetate (PIDA) as N-acylation agent

An effective method was explored for the one-pot synthesis of N-acylated urea derivatives by the reaction of substituted isothiocyanatobenzenes, primary amines and PIDA (phenyliodine (III) diacetate) in one-pot manner. Mild reaction conditions, short reaction time, high efficiency and readily accessible materials are the features of this method, making suitable and alternative for the preparation of a variety of biologically or pharmaceutically active compounds.

Visible-Light-Induced Metal- and Photocatalyst-Free Radical Cascade Cyclization of Cinnamamides for Synthesis of Functionalized Dihydroquinolinones.

Visible-light-promoted metal- and photocatalyst-free radical cascade cyclization of cinnamamides with α-oxocarboxylic acids is described for sustainable synthesis of diverse pharmaceutically important dihydroquinolinone scaffolds in one pot under mild conditions. The decarboxylative cascade cyclization proceeded efficiently at room temperature without the need for expensive photocatalysts such as Ir or Ru complexes, which indicates the practicability and environmentally benign nature of this protocol. Preliminary mechanistic studies reveal that the blue LED irradiation efficiently cleaves the I-O bond of the hypervalent iodine reagent PhI(O2CCOAr)2 formed through ligand exchange between iodobenzene diacetate and arylglyoxylic acid to initiate the cascade reaction. The synthetic value of this operationally simple and energy-efficient method is further demonstrated by late-stage functionalization of drug molecules in excellent yields.

Synthesis of 2-Fluoroalkylated Oxazoles from β-Monosubstituted Enamines via Fluoroacyloxylation and Cyclization Mediated by Fluoroalkyl-Containing Hypervalent Iodine(III) Species Generated In Situ.

A metal-free synthesis of a series of fluoroalkyl-containing oxazoles from β-monosubstituted enamines was developed. This fluoroacyloxylation/cyclization cascade process was mediated by fluoroalkyl-containing hypervalent iodine(III) species formed in situ from the reaction of phenyliodine(III) diacetate (PIDA) and RCF2CO2H (R = H, Cl, Br, F, CF3, CH3, Ph, SAr, OAr).

PhI(OAc)2‐Mediated One‐Pot Oxidative [3+2] Cycloaddition/ Heterocyclization Reactions of Aldoximes with N‐Arylmaleimides: A Facile Access to N‐Substituted Pyrrolo‐Isoxazoles

AbstractA convenient and efficient metal‐free oxidative [3+2] cycloaddition reaction of N‐arylmaleimides with nitrile oxides generated in situ from the corresponding aldoximes using diacetoxyiodobenzene (DIB) as hypervalent iodine reagent under mild conditions has been established. The one‐pot oxidative cycloaddition afforded corresponding bioinspired bicyclic isoxazole/pyrrolo‐isoxazole derivatives in up to 91 % yield at room temperature. To demonstrate the efficacy of this methodology, the reaction was scaled up to the gram‐scale showing synthetic potential in industrial application. The one‐pot fashion makes the strategy highly time‐economic, atom‐economic and minimizes chemical waste by circumventing several purification steps.

On Water Synthesis of 3-Aryl-1,2,4-Triazolo[4,3-a]Pyridines Using Iodobenzene Diacetate (IBD)

Abstract: An iodobenzene diacetate (IBD)-mediated simple and green method was determined for the intramolecular oxidative cyclization of 3-aryl-2-pyridiylhydrazones of different aromatic aldehydes in an aqueous medium at room temperature. This efficient strategy provides a route to the synthesis of 3-aryl-1,2,4-triazolo[4,3-a]pyridines in water which eliminates the requirement to use costly and unsafe volatile organic solvents. All reactions were carried out by just stirring the reaction components in water at room temperature. This protocol provides a wide substrate scope and good functional group tolerance.

Synthesis, characterization and application of a highly dispersed and reactive hypervalent iodine(V)/polyvinylpyrrolidone dendrimer nanocomposite: Hetero- vs. homo-intermolecular secondary O---I bonds

Polyvinylpyrrolidone (PVP) assisted aerobic oxidation of bulk iodosylbenzene or hydrolysis/oxidation of iodobenzene diacetate under mild conditions leading to the formation of nanostructured iodylbenzene is reported. AFM and FESEM-EDX analyses confirmed the formation of dendrimer iodylbenzene-polyvinylpyrrolidone nanocomposite (PhIO2-PVP) through the two top-down approaches. The formation of PhIO2 was confirmed by 1H NMR spectroscopy. Strong interactions between iodylbenzene molecules and the polymer through secondary intermolecular O---I bonds was evident from the large difference between the morphology of PVP (cubic) and PhIO2-PVP (dendrimer) nanoparticles. FESEM images showed a maximum width and length of 70 and 1000 nm for the dendrimers, respectively. The dual role played by PVP, i.e., facilitating the oxidation of I(III) to I(V) and stabilization the hypervalent I(V) compound was attributed to the formation of strong secondary hetero-intermolecular O---I bonds, between the polymer and iodine centre. The very fine aqueous and dichloromethane suspensions of PhIO2-PVP were indistinguishable to the naked eye. Efficient direct oxidation of cyclohexene and methylene blue with PhIO2-PVP at room temperature and a short reaction time provided evidence of significantly increased reactivity of PhIO2-PVP compared to that of the bulk oxidant. PhIO2-PVP was also used in the oxidation of methyl phenyl sulfide and styrene in water and dichloroethane, using water soluble and insoluble metalloporphyrins, respectively. The former led to the formation of the corresponding sulfoxide as the sole product in the two solvents. In addition to styrene oxide formed in both solvents, benzaldehyde was also formed with a selectivity of 24% in water. Almost complete oxidation of the organic substrates was observed in dichloroethane. The results of this study show that the nanostructured iodine(V) compound can be used as an efficient terminal oxidant in biomimetic oxidations.

On Water Synthesis of 3-Aryl-5,7-dimethyl-1,2,4-triazolo[4,3-a]pyrimidines using Iodobenzene Diacetate

Abstract:A simple and green methodology has been developed for the synthesis of 3-aryl-5,7- dimethyl-1,2,4-triazolo[4,3-a]pyrimidines in water. Oxidative cyclization of 4,6-dimethyl-2- pyrimidinylhydrazones of different aldehydes was achieved in good to excellent yield using iodobenzene diacetate at room temperature. High efficiency, easy work-up, short reaction time, non-toxicity of solvent and ambient temperature are the advantages of this methodology.

Applications of phenyliodine(III) diacetate in heterocyclic ringformations: An updatefrom 2015 to date

AbstractDiacetoxyiodobenzene (PhI(OAc)2), commonly referred to asDAIBor phenyliodine(III) diacetate (PIDA), is one of the most frequently used hypervalent iodines employed as an oxidizing agent in organic chemistry. In this review,PIDAis highlighted exclusively in relation to its applications in organic synthesis involving heterocyclic ring formations and is critically and in‐depth examined from the summer of 2015 to the present with a specific focus on the mechanistic pathway.

Synthesis of 3-Haloindoles via Cascade Oxidative Cyclization/Halogenation of 2-Alkenylanilines Mediated by PIDA and LiBr/KI

The treatment of 2-alkenylanilines with phenyliodine(III) diacetate (PIDA) and LiBr or KI in HFIP was found to afford the corresponding 3-haloindoles via cascade oxidative cyclization/halogenation encompassing oxidative C-N/C-X (X = Br, I) bond formations. A plausible mechanism involving the in situ formation of the reactive AcO-X (X = Br, I) from the reaction of PIDA and LiBr/KI was postulated.

Chemoselective synthesis of α-carboline derivatives via hypervalent iodine-catalyzed [3+3] annulation under metal-free conditions

A strategy for the synthesis of α-carboline derivatives from indole-3-carboxaldehydes and 3-aminocyclohex-2-enones under metal-free conditions has been developed. The combination use of phenyliodine (III) diacetate (PIDA) and benzoic acid could significantly facilitate the corresponding [3 ​+ ​3] annulation process. This newly developed strategy featured unextraordinary chemoselectivity, good functional group tolerance and the preservation of the carbonyl group of the ketone substrates, which offers the possibility for further transformation of the products.

Applications of Phenyliodine(III)diacetate in C−H Functionalization and Hetero‐Hetero Bond Formations: A Septennial Update

AbstractOne of the most widely utilized hypervalent iodines used as an oxidizing agent in organic chemistry is (diacetoxyiodo)benzene (PhI(OAc)2), also known as (DAIB), phenyliodine(III) diacetate (PIDA). In this review, authors have comprehensively and systematically presented the various applications of PIDA in organic synthesis involving C−C, C‐hetero, hetero‐hetero and multiple bond forms from the summer of 2015 to the present. The role of PIDA was also emphasized for the success of particular organic transformation. Recent literature has produced a substantial number of publications (∼100), and this septennial review examines all of the most recent breakthroughs in the field of study.

Stereoselective oxidative O-glycosylation of disarmed glycosyl iodides with alcohols using PIDA as the promoter.

The direct and practical oxidative anomeric O-glycosylation of glycosyl iodides with an array of alcohols as glycosyl acceptors is presented. Using phenyliodine(III) diacetate (PIDA) as the promoter of the reaction, at ambient temperature, an enviromentally benign and operationally simple protocol has been developed providing access stereoselectively to 1,2-trans-O-glycosides.