Synthesis of Benzimidazolones via One-Pot Reaction of Hydroxylamines, Aldehydes, and Trimethylsilyl Cyanide Promoted by Diacetoxyiodobenzene

Zhang, Huaiyuan; Huang, Danfeng; Wang, Ke‐Hu; Li, Jun; Su, Yingpeng; Hu, Yulai

doi:10.1021/acs.joc.6b02781

Cited by 17 publications

(10 citation statements)

References 40 publications

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“…In order to improve the electrical and electro-optic properties of LC materials, great efforts have been made to attach C 60 covalently to mesogens as well as to dope C 60 into LC matrices [95,[202][203][204]. The recent, significant developments in fullerene-containing LCs have been reviewed by Zhang et al [205].…”

Section: Modification Of Physical Properties Of Lc Materials By Nanodmentioning

confidence: 99%

Perspectives in Liquid-Crystal-Aided Nanotechnology and Nanoscience

2019

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The research field of liquid crystals and their applications is recently changing from being largely focused on display applications and optical shutter elements in various fields, to quite novel and diverse applications in the area of nanotechnology and nanoscience. Functional nanoparticles have recently been used to a significant extent to modify the physical properties of liquid crystals by the addition of ferroelectric and magnetic particles of different shapes, such as arbitrary and spherical, rods, wires and discs. Also, particles influencing optical properties are increasingly popular, such as quantum dots, plasmonic, semiconductors and metamaterials. The self-organization of liquid crystals is exploited to order templates and orient nanoparticles. Similarly, nanoparticles such as rods, nanotubes and graphene oxide are shown to form lyotropic liquid crystal phases in the presence of isotropic host solvents. These effects lead to a wealth of novel applications, many of which will be reviewed in this publication. the observation of chirality from achiral molecules, resulting from sterically induced packing of the bent-core mesogens [10], such as ferroelectricity or the formation of helical superstructures in the B7 phase [14]. Thermotropic LCs are commonly constituted by single organic entities or mixtures thereof, which exhibit various mesophases at different temperatures or pressures [15], illustrated in Figure 1b. As the temperature rises, a typical thermotropic LC passes through higher ordered phases, also called soft crystals, the hexatic smectic phases with positional order as well as bond orientational order, through the fluid smectic phases (SmC and SmA), which exhibit both positional and orientational order, and finally to the nematic phase (N) with purely orientational order, into the isotropic phase. The number of different phases observed depends on the chemical composition, symmetry and order of the LC molecules. About 25 different thermotropic phases are known to date, and they are still increasing in number. Appl. Sci. 2019, 9, x FOR PEER REVIEW 2 of 47 unique effects of the observation of chirality from achiral molecules, resulting from sterically induced packing of the bent-core mesogens [10], such as ferroelectricity or the formation of helical superstructures in the B7 phase [14]. Thermotropic LCs are commonly constituted by single organic entities or mixtures thereof, which exhibit various mesophases at different temperatures or pressures [15], illustrated in Figure 1b. As the temperature rises, a typical thermotropic LC passes through higher ordered phases, also called soft crystals, the hexatic smectic phases with positional order as well as bond orientational order, through the fluid smectic phases (SmC and SmA), which exhibit both positional and orientational order, and finally to the nematic phase (N) with purely orientational order, into the isotropic phase. The number of different phases observed depends on the chemical composition, symmetry and order of the LC molecules. About...

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Section: Modification Of Physical Properties Of Lc Materials By Nanodmentioning

confidence: 99%

Perspectives in Liquid-Crystal-Aided Nanotechnology and Nanoscience

2019

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“…Hypervalent iodine(III) compounds have attracted much attention as oxidants in organic synthesis, as they can be a replacement for transition metals with the advantage of having environmentally benign properties. − Although iodine(III) reagents are competent to conduct many organic transformations, addition of a Lewis acid such as BF 3 is often a prerequisite for a process to occur. For example, it has been shown that an iodine(III) reagent in conjunction with BF 3 ·Et 2 O considerably accelerates the processes that yield λ 3 -diaryliodanes, olefin diacetoxylation, and a plethora of other products. − In this context, Ochiai et al reported that alcohols can be selectively oxidized by hypervalent iodine(III) compound 2 to aldehydes or ketones in the presence of BF 3 ·Et 2 O as the catalyst (Scheme ). For this catalytic reaction, the first step is proposed to be a ligand exchange between iodine(III) reagent 2 and the alcohol, followed by a redox process to give the final product.…”

Section: Introductionmentioning

confidence: 99%

DFT Mechanistic Investigation into BF₃-Catalyzed Alcohol Oxidation by a Hypervalent Iodine(III) Compound

et al. 2019

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Density functional theory (DFT) at the SMD/M06-2X/def2-TZVP//SMD/M06-2X/LANL2DZ,6-31G(d) level was employed to explore mechanistic aspects of BF3-catalyzed alcohol oxidation using a hypervalent iodine(III) compound, [ArI(OAc)2], to yield aldehydes/ketones as the final products. The reaction is composed of two main processes: (i) ligand exchange and (ii) the redox reaction. Our study for 1-propanol discovered that ligand exchange is preferentially accelerated if BF3 first coordinates to the alcohol. This coordination increases the acidity of the alcohol hydroxyl proton, resulting in ligand exchange between the iodane and the alcohol proceeding via a concerted interchange associative mechanism with an activation free energy of ∼10 kcal/mol. For the redox process, the calculations rule out the feasibility of the conventional mechanism (alkoxy Cα deprotonation) and introduce a replacement for it. This alternative route commences with α-hydride elimination of the alkoxy group promoted by BF3 coordination, which yields a BF3-stabilized aldehyde/ketone product and the iodane [ArI(OAc)(H)]. The ensuing iodane is extremely reactive toward reductive elimination to give ArI + HOAc in a highly exergonic fashion (ΔG = −62.1 kcal/mol). The reductive elimination reaction is the thermodynamic driving force for the alcohol oxidation to be irreversible. Consistent with the kinetic isotope effect reported experimentally, the α-hydride elimination is calculated to be the rate-determining step with an overall activation free energy of ∼24 kcal/mol.

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“…The synthetic methods of benzimidazolone can be classied into 6 types (Scheme 2). 14,15 Firstly, benzimidazolone is commonly synthesized by cyclocarbonylation of ortho-substituted anilines 1 and various carbonyl reagents according to related references. For example, Bhanage et al 16 reported that benzimidazolone was obtained in 98% yields from the reaction of urea with 1,2-diaminobenzene without any catalysts under a reduced pressure.…”

Section: Synthesis Of Benzimidazolonementioning

confidence: 99%

The methodology for preparing domperidone: strategies, routes and reaction processes

Shao

Guo

et al. 2022

RSC Adv.

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Synthesis of Benzimidazolones via One-Pot Reaction of Hydroxylamines, Aldehydes, and Trimethylsilyl Cyanide Promoted by Diacetoxyiodobenzene

Cited by 17 publications

References 40 publications

Perspectives in Liquid-Crystal-Aided Nanotechnology and Nanoscience

Perspectives in Liquid-Crystal-Aided Nanotechnology and Nanoscience

DFT Mechanistic Investigation into BF₃-Catalyzed Alcohol Oxidation by a Hypervalent Iodine(III) Compound

The methodology for preparing domperidone: strategies, routes and reaction processes

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Synthesis of Benzimidazolones via One-Pot Reaction of Hydroxylamines, Aldehydes, and Trimethylsilyl Cyanide Promoted by Diacetoxyiodobenzene

Cited by 17 publications

References 40 publications

Perspectives in Liquid-Crystal-Aided Nanotechnology and Nanoscience

Perspectives in Liquid-Crystal-Aided Nanotechnology and Nanoscience

DFT Mechanistic Investigation into BF3-Catalyzed Alcohol Oxidation by a Hypervalent Iodine(III) Compound

The methodology for preparing domperidone: strategies, routes and reaction processes

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Product

Resources

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DFT Mechanistic Investigation into BF₃-Catalyzed Alcohol Oxidation by a Hypervalent Iodine(III) Compound