scholarly journals Copper-Catalyzed Insertion of Diazo Compounds into Vinyl Hypervalent Iodine Reagents to Generate Allylic Esters

2019 ◽  
Author(s):  
Guillaume Pisella ◽  
Alec Gagnebin ◽  
Jerome Waser
Keyword(s):  
Functional Groups ◽  
Allylic Alcohol ◽  
Diazo Compounds ◽  
Hypervalent Iodine ◽  
Aryl Iodide ◽  
Broad Scope ◽  
Donor And Acceptor ◽  
Leaving Group ◽  
Donor Acceptor ◽  
Allylic Esters

An unprecedented copper(I)-catalyzed vinylation of (donor)-acceptor diazo compounds with VinylBenziodoXolone reagents (VBX) as partners is reported. The transformation tolerates variation of both donor- and acceptor substituents on the diazo compounds, delivering the corresponding benzoylated allylic alcohol products in good to excellent yields. Through the development of a protocol for the synthesis of functionalized alkanes-, dienes- and enynes-substituted VBX reagents, a broad scope of substituents on the alkene could be accessed. The obtained products contain synthetically versatile functional groups, such as an aryl iodide, an ester and an allylic leaving group, enabling selective further modification.

scholarly journals Copper-Catalyzed Insertion of Diazo Compounds into Vinyl Hypervalent Iodine Reagents to Generate Allylic Esters

2019 ◽  
Author(s):  
Guillaume Pisella ◽  
Alec Gagnebin ◽  
Jerome Waser
Keyword(s):  
Functional Groups ◽  
Allylic Alcohol ◽  
Diazo Compounds ◽  
Hypervalent Iodine ◽  
Aryl Iodide ◽  
Broad Scope ◽  
Donor And Acceptor ◽  
Leaving Group ◽  
Donor Acceptor ◽  
Allylic Esters

An unprecedented copper(I)-catalyzed vinylation of (donor)-acceptor diazo compounds with VinylBenziodoXolone reagents (VBX) as partners is reported. The transformation tolerates variation of both donor- and acceptor substituents on the diazo compounds, delivering the corresponding benzoylated allylic alcohol products in good to excellent yields. Through the development of a protocol for the synthesis of functionalized alkanes-, dienes- and enynes-substituted VBX reagents, a broad scope of substituents on the alkene could be accessed. The obtained products contain synthetically versatile functional groups, such as an aryl iodide, an ester and an allylic leaving group, enabling selective further modification.

scholarly journals Thermochromic aggregation-induced dual phosphorescence via temperature-dependent sp3-linked donor-acceptor electronic coupling

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Tao Wang ◽  
Zhubin Hu ◽  
Xiancheng Nie ◽  
Linkun Huang ◽  
Miao Hui ◽  
...  
Keyword(s):  
Excited State ◽  
Room Temperature ◽  
Electronic Coupling ◽  
Temperature Dependent ◽  
Molecular Systems ◽  
Donor And Acceptor ◽  
Theoretical Investigations ◽  
Donor Acceptor ◽  
And Control ◽  
Two Temperature

AbstractAggregation-induced emission (AIE) has proven to be a viable strategy to achieve highly efficient room temperature phosphorescence (RTP) in bulk by restricting molecular motions. Here, we show that by utilizing triphenylamine (TPA) as an electronic donor that connects to an acceptor via an sp3 linker, six TPA-based AIE-active RTP luminophores were obtained. Distinct dual phosphorescence bands emitting from largely localized donor and acceptor triplet emitting states could be recorded at lowered temperatures; at room temperature, only a merged RTP band is present. Theoretical investigations reveal that the two temperature-dependent phosphorescence bands both originate from local/global minima from the lowest triplet excited state (T1). The reported molecular construct serves as an intermediary case between a fully conjugated donor-acceptor system and a donor/acceptor binary mix, which may provide important clues on the design and control of high-freedom molecular systems with complex excited-state dynamics.

scholarly journals Supramolecular Systems Containing B–N Frustrated Lewis Pairs of Tris(pentafluorophenyl)borane and Triphenylamine Derivatives

2021 ◽  
Vol 03 (02) ◽  
pp. 174-183
Author(s):  
P. Chidchob ◽  
S. A. H. Jansen ◽  
S. C. J. Meskers ◽  
E. Weyandt ◽  
N. P. van Leest ◽  
...  
Keyword(s):  
Materials Science ◽  
Supramolecular Polymers ◽  
Frustrated Lewis Pairs ◽  
Paramagnetic Resonance ◽  
Donor And Acceptor ◽  
Donor Acceptor ◽  
Noncovalent Polymers ◽  
Electron Paramagnetic ◽  
Supramolecular Polymerization ◽  
Lewis Pairs

The introduction of a chemical additive to supramolecular polymers holds high potential in the development of new structures and functions. In this regard, various donor- and acceptor-based molecules have been applied in the design of these noncovalent polymers. However, the incorporation of boron–nitrogen frustrated Lewis pairs in such architectures is still rare despite their many intriguing properties in catalysis and materials science. The limited choices of suitable boron derivatives represent one of the main limitations for the advancement in this direction. Here, we examine the use of the commercially available tris(pentafluorophenyl)borane with various triphenylamine derivatives to create supramolecular B–N charge transfer systems. Our results highlight the importance of a proper balance between the donor/acceptor strength and the driving force for supramolecular polymerization to achieve stable, long-range ordered B–N systems. Detailed analyses using electron paramagnetic resonance and optical spectroscopy suggest that tris(pentafluorophenyl)borane displays complex behavior with the amide-based triphenylamine supramolecular polymers and may interact in dimers or larger chiral aggregates, depending on the specific structure of the triphenylamines.

Silver-Catalyzed Cross-Olefination of Donor and Acceptor Diazo Compounds: Use ofN-Nosylhydrazones as Diazo Surrogate

2017 ◽  
Vol 2017 (4) ◽  
pp. 928-932 ◽  
Author(s):  
Zhaohong Liu ◽  
Binbin Liu ◽  
Xue-Feng Zhao ◽  
Yan-Bo Wu ◽  
Xihe Bi
Keyword(s):  
Diazo Compounds ◽  
Donor And Acceptor

Ligand-Free Pd-Catalyzed Highly Selective Arylation of Allylic Esters with Retention of the Traditional Leaving Group

2008 ◽  
Vol 120 (25) ◽  
pp. 4807-4810 ◽  
Author(s):  
Delin Pan ◽  
Anjun Chen ◽  
Yijin Su ◽  
Wang Zhou ◽  
Si Li ◽  
...  
Keyword(s):  
Ligand Free ◽  
Leaving Group ◽  
Allylic Esters

Controlling charge transfer in fullerene/phthalocyanine electron donor-acceptor conjugates/hybrids

2009 ◽  
Vol 13 (10) ◽  
pp. 1034-1039 ◽  
Author(s):  
Wolfgang Seitz ◽  
Axel Kahnt ◽  
Dirk M. Guldi ◽  
Tomas Torres
Keyword(s):  
Three Dimensional ◽  
Reorganization Energy ◽  
Model Systems ◽  
Transfer Reactions ◽  
Dimensional Electron ◽  
Specific Composition ◽  
Donor And Acceptor ◽  
Donor Acceptor ◽  
Light Harvesting Antenna ◽  
Energetic Charge

Fullerenes and phthalocyanines are ideally suited for devising integrated, multi-component model systems to transmit and process solar energy. Implementation of C 60 as a three-dimensional electron acceptor bears great promises on account of its small reorganization energy in electron transfer reactions and has exerted a noteworthy impact on the improvement of light-induced charge separation. This mini-review describes how the specific composition of phthalocyanines chromophores associated with C 60 – yielding artificial light-harvesting antenna and reaction center mimics – have been elegantly utilized to tune the electronic couplings between donor and acceptor sites. Specifically, the effects that these parameters have on the rate, yield and lifetime of the energetic charge-separated states are considered.

scholarly journals Palladium-Catalyzed [3+2] Cycloaddition via Two-Fold 1,3-C(sp3)−H Activation

2020 ◽  
Author(s):  
Hojoon Park ◽  
jin-quan yu
Keyword(s):  
Functional Groups ◽  
Sulfonic Acid ◽  
Cycloaddition Reaction ◽  
Wide Range ◽  
Leaving Group ◽  
Palladium Catalyzed ◽  
Directing Group ◽  
Overall Efficiency ◽  
Weak Coordination ◽  
Single Reaction

<div>Cycloaddition reactions provide an expeditious route to construct ring systems in a highly convergent and stereoselective manner. For a typical cycloaddition reaction to occur, however, the installation of multiple reactive functional groups (π-bonds, leaving group, etc.) are required within the substrates, compromising the overall efficiency or scope of the cycloaddition reaction. Here, we report a palladium-catalyzed [3+2] reaction that utilizes C(sp<sup>3</sup>)–H activation to generate the three-carbon unit for formal cycloaddition with maleimides. We implemented a strategy where the initial C(sp<sup>3</sup>)–H activation/olefin insertion would trigger a relayed, second remote C(sp<sup>3</sup>)–H activation to complete a formal [3+2] cycloaddition. The diastereoselectivity profile of this reaction resembles that of a typical pericyclic cycloaddition reaction in that the relationships between multiple stereocenters are exquisitely controlled in a single reaction. The key to success was the use of weakly coordinating amides as the directing group, as undesired Heck or alkylation pathways were preferred with other types of directing groups. The use of the pyridine-3-sulfonic acid ligands is critical to enable C(sp<sup>3</sup>)–H activation directed by this weak coordination. The method is compatible with a wide range of amide substrates, including lactams, which lead to novel spiro-bicyclic products. The [3+2] product is also shown to undergo a reductive desymmetrization process to access chiral cyclopentane bearing multiple stereocenters with excellent enantioselectivity.</div>

Convenient Synthesis of Oxazolo[5,4-h]pyrrolo[4,3,2-de]quino­lones via Hypervalent Iodine Mediated Intramolecular Oxidative Cyclization

Synthesis ◽  
2017 ◽  
Vol 28 (19) ◽  
pp. 4517-4522
Author(s):  
Li-Ping Sun ◽  
Chun-Meng Wang ◽  
Sheng-Wei Yang ◽  
Kai-Xiang Tang ◽  
Tian-Hong Gao ◽  
...  
Keyword(s):  
Functional Groups ◽  
Practical Method ◽  
Oxidative Cyclization ◽  
Hypervalent Iodine ◽  
Air Atmosphere ◽  
Convenient Synthesis ◽  
Reaction Proceeds ◽  
Intramolecular Oxidative Cyclization

A convenient and practical method has been developed for the synthesis of substituted oxazolo[5,4-h]pyrrolo[4,3,2-de]quinolones via the intramolecular oxidative cyclization by using PIFA as oxidant and TMSOTf as additive in DCE under an air atmosphere. The reaction proceeds in good yields and has good functional groups tolerance.

scholarly journals Spectral fine tuning of cyanine dyes: electron donor–acceptor substituted analogues of thiazole orange

2015 ◽  
Vol 14 (9) ◽  
pp. 1703-1712 ◽  
Author(s):  
Elizabeth E. Rastede ◽  
Matteus Tanha ◽  
David Yaron ◽  
Simon C. Watkins ◽  
Alan S. Waggoner ◽  
...  
Keyword(s):  
Electron Donor ◽  
Emission Spectra ◽  
Fine Tuning ◽  
Cyanine Dye ◽  
Thiazole Orange ◽  
Absorption And Emission ◽  
Donor And Acceptor ◽  
Dye Absorption ◽  
Donor Acceptor ◽  
Electron Donor And Acceptor

Strategically placed electron donor and acceptor groups allow fine-tuning of cyanine dye absorption and emission spectra while preserving recognition of biomolecular hosts such as DNA and proteins.

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